Design of Secure Hash Algorithm(SHA)
0 likes607 views
The document discusses the design of secure hash algorithms SHA-256 and SHA-3. SHA-256 has a block size of 512 bits and processes messages in 64 rounds. SHA-3 uses a sponge construction that absorbs data into a state and then squeezes out the output hash. Both algorithms are used to secure blockchains like Bitcoin and Ethereum.
1 of 22
Download to read offline
Ad
Recommended
Hash Function
Hash FunctionSiddharth Srivastava This document discusses message authentication techniques including message encryption, message authentication codes (MACs), and hash functions. It describes how each technique can be used to authenticate messages and protect against various security threats. It also covers how symmetric and asymmetric encryption can provide authentication when used with MACs or digital signatures. Specific MAC and hash functions are examined like HMAC, SHA-1, and SHA-2. X.509 is introduced as a standard for digital certificates.
SHA- Secure hashing algorithm
SHA- Secure hashing algorithmRuchi Maurya This document outlines the Secure Hashing Algorithm (SHA), focusing on SHA-1, developed by NIST and NSA in 1993 as a federal information processing standard. It details the functioning of SHA-1, including its input requirements, operational steps, and the processing of 512-bit blocks through multiple rounds and iterations. The algorithm is used in various applications, such as secure password hashing and digital signatures.
Cryptography - 101
Cryptography - 101n|u - The Open Security Community This document provides an overview of cryptography concepts including symmetric and asymmetric key algorithms, cryptographic hashes, and tools for cryptanalysis. It defines common terminology like plaintext, ciphertext, encryption, and decryption. Symmetric algorithms discussed include the Vernam cipher, A5/1, DES, AES, and RC4. Asymmetric algorithms covered are RSA and Diffie-Hellman key exchange. Cryptographic hashes like MD5 and SHA-1 are also summarized along with resources for cryptanalysis.
Block cipher modes of operation
Block cipher modes of operation harshit chavda The document describes block ciphers, a foundational element in cryptography that encrypts fixed-length blocks of data using symmetric keys. It outlines five modes of operation defined by NIST to handle messages of varying lengths, including Electronic Codebook (ECB), Cipher Block Chaining (CBC), Cipher Feedback (CFB), Output Feedback (OFB), and Counter mode (CTR), each with specific encryption and decryption processes as well as security considerations. The text highlights the importance of initialization vectors (IVs) in ensuring encryption security and explains vulnerabilities associated with reusing IVs and patterns in ciphertext.
How Hashing Algorithms Work
How Hashing Algorithms WorkCheapSSLsecurity The document provides a comprehensive overview of hashing algorithms, detailing their purpose in ensuring data integrity by converting inputs into fixed-size hash values. Key characteristics include irreversibility and uniqueness, with hash functions playing a crucial role in this process. Popular hashing algorithms such as SHA and MD are also mentioned, emphasizing the importance of these algorithms in various applications like password storage and data comparison.
Cryptography
Cryptographysubodh pawar Cryptography is a method used for securely storing and transmitting data, ensuring that only intended recipients can access it. The document explores the history, types (symmetric and asymmetric), and techniques of cryptography, including classical and modern methods, along with algorithms like DES and AES. It emphasizes the importance of cryptography in maintaining data confidentiality, integrity, and secure communication across various applications.
Message digest 5
Message digest 5Tirthika Bandi MD5 is a cryptographic hash function that produces a 128-bit hash value for a message of any length. It was originally designed to provide authentication of digital signatures but is no longer considered reliable for cryptography due to techniques that can generate collisions. MD5 operates by padding the input, appending the length, dividing into blocks, initializing variables, processing blocks through 4 rounds of operations with different constants each round, and outputting the hash value. While it was intended to be difficult to find collisions or recover the input, MD5 is no longer considered cryptographically secure due to attacks demonstrating collisions.
Cryptographic algorithms
Cryptographic algorithmsAnamika Singh The document summarizes cryptographic algorithms DES and AES. It describes the basic concepts of encryption, the history and workings of DES including key generation and encryption/decryption processes. It then explains the AES cipher which was selected to replace DES, including the cipher structure involving substitution, shifting, mixing and adding round keys in multiple rounds of processing. The key expansion process is also summarized, which derives the round keys from the main encryption key.
Encryption And Decryption Using AES Algorithm
Encryption And Decryption Using AES AlgorithmAhmed Raza Shaikh The document discusses encryption and decryption, emphasizing their importance in securing sensitive data. It focuses on the Advanced Encryption Standard (AES), a symmetric block cipher used to protect classified information, highlighting its three variants (AES-128, AES-192, AES-256) and the uniformity of key lengths for data protection. Additionally, it describes a project that employs AES to encrypt and decrypt text files using Java code, ensuring secure communication between parties.
Hash Function
Hash Functionstalin rijal A hash function maps data of arbitrary size to a fixed size value called a hash. Common hash functions include MD5 and SHA, with MD5 producing a 128-bit hash. While hashes were once used to securely store passwords, MD5 is now considered cryptographically broken due to collisions being found in its compression function. One-way signatures allow multiple users to generate linked signatures on the same message in a verifiable chain.
MD5 ALGORITHM.pptx
MD5 ALGORITHM.pptxRajapriya82 The MD5 algorithm is a cryptographic hash function that generates a 128-bit digest from a message of any length. It works by first padding the message to a length that is a multiple of 512 bits, then appending the message length. It initializes buffers and processes the message in 512-bit blocks using four rounds of 16 operations each, applying different functions to update the buffers. The final buffer values become the MD5 digest. It is commonly used to verify file integrity but is now considered insecure due to possible hash collisions.
Transport Layer Security (TLS)
Transport Layer Security (TLS)Arun Shukla Transport Layer Security (TLS) is a protocol that ensures privacy and security between communicating applications on the internet, succeeding the older Secure Sockets Layer (SSL). The TLS protocol consists of a handshake mechanism for authentication and key exchange, and a record protocol for securing application data. It allows for encrypted communication by negotiating cipher suites and generating session keys, thereby preventing eavesdropping and tampering.
Principles of public key cryptography and its Uses
Principles of public key cryptography and its UsesMohsin Ali This document discusses the principles of public key cryptography. It begins by defining asymmetric encryption and how it uses a public key and private key instead of a single shared key. It then discusses key concepts like digital certificates and public key infrastructure. The document also provides examples of how public key cryptography can be used, including the RSA algorithm and key distribution methods like public key directories and certificates. It explains how public key cryptography solves the key distribution problem present in symmetric encryption.
Cryptography
CryptographyDarshini Parikh Cryptography is the practice and study of securing communication through techniques like encryption. It has evolved through manual, mechanical, and modern eras using computers. Cryptography aims to achieve goals like authentication, confidentiality, integrity, and non-repudiation. Common attacks include brute force, chosen plaintext, and differential power analysis. Symmetric cryptography uses a shared key while asymmetric uses public/private key pairs. Digital signatures and watermarks can authenticate documents. DRM and watermarks control digital content distribution.
DES (Data Encryption Standard) pressentation
DES (Data Encryption Standard) pressentationsarhadisoftengg This document discusses data encryption methods. It defines encryption as hiding information so it can only be accessed by those with the key. There are two main types: symmetric encryption uses one key, while asymmetric encryption uses two different but related keys. Encryption works by scrambling data using techniques like transposition, which rearranges the order, and substitution, which replaces parts with other values. The document specifically describes the Data Encryption Standard (DES) algorithm and the public key cryptosystem, which introduced the innovative approach of using different keys for encryption and decryption.
Key management and distribution
Key management and distributionRiya Choudhary Key management is the set of techniques and procedures for establishing and maintaining secure key relationships between parties. It involves generating, distributing, storing, updating, and revoking cryptographic keys. The objectives of key management are to maintain secure keying material and relationships to counter relevant threats like key compromise, in accordance with a security policy. Techniques include symmetric and public-key encryption, key hierarchies, certificates, and life cycle processes around user registration and key installation, update, and destruction.
CS6701 CRYPTOGRAPHY AND NETWORK SECURITY
CS6701 CRYPTOGRAPHY AND NETWORK SECURITYKathirvel Ayyaswamy The document outlines the concepts and mechanisms of email, IP, and web security, focusing on email security services like confidentiality, authentication, and non-repudiation, as well as attacks like phishing. It discusses encryption methods and protocols such as PGP and S/MIME for secure communications, and details the complex framework of IP security (IPsec) covering its architecture, operations, and key management. Additionally, the document describes SSL/TLS for web security, emphasizing the importance of these security measures in protecting information across networks.
Encryption
Encryptionkeith dias The document provides information about encryption and decryption techniques. It defines encryption as converting plaintext into ciphertext and decryption as converting ciphertext back to plaintext. It discusses symmetric encryption which uses the same key for encryption and decryption, and asymmetric encryption which uses public/private key pairs. Specific symmetric algorithms like DES and AES are covered as well as the asymmetric RSA algorithm. Different block cipher modes of operation like ECB, CBC, CFB and OFB are also summarized.
Hash function
Hash functionHarry Potter The document discusses hash functions and message authentication codes (MACs). It begins by defining hash functions and MACs, noting that hash functions generate a fingerprint for a message without a key while MACs use a keyed hash function. It then covers security requirements for hash functions like one-wayness and collision resistance. Popular hash functions are described like MD5, SHA-1, and the SHA-2 family. Constructions for hash functions based on block ciphers and iterated hash functions are also outlined. The document concludes by comparing hash functions and MACs and describing common MAC constructions.
Message authentication
Message authenticationCAS The document discusses computer security focusing on message authentication, highlighting the requirements for message integrity and sender validation. It covers methods such as symmetric and public-key encryption, hash functions, message authentication codes (MAC), and HMAC, explaining their roles in ensuring message security against various attacks. The content serves as an outline for effective communication protocol management in IT, emphasizing the importance of confidentiality and authentication mechanisms.
Public key Infrastructure (PKI)
Public key Infrastructure (PKI)Venkatesh Jambulingam The document discusses Public Key Infrastructure (PKI), highlighting its role in secure online transactions through the use of digital certificates, encryption methods, and trust services. It explains the components of PKI, including registration and certificate authorities, as well as digital signature processes and certificate-based authentication methods. Overall, the content emphasizes ensuring secure communication and verifying identities in the digital realm.
Diffie hellman key exchange algorithm
Diffie hellman key exchange algorithmSunita Kharayat The document explains the Diffie-Hellman key exchange, a foundational method for securely sharing cryptographic keys over a public channel, introduced by Whitfield Diffie and Martin Hellman in 1976. It outlines the algorithm's mechanics, including the use of prime numbers and primitive roots, and discusses potential vulnerabilities, such as the man-in-the-middle attack. Additionally, it presents alternative solutions for secure communication, such as the key distribution center (KDC) while highlighting the challenges associated with replay attacks.
Hash Function
Hash Function ssuserdfb2da This document discusses cryptographic hash functions including their applications in message authentication and digital signatures. It describes the requirements for hash functions to be secure including resistance to brute force attacks and cryptanalysis. The document outlines some simple hash functions and provides details on the Secure Hash Algorithm (SHA) family of cryptographic hash functions used in standards like SHA-512 which operates on 1024-bit blocks through 80 rounds. It also mentions NIST's selection of the Keccak algorithm as the new SHA-3 standard.
Message Authentication Code & HMAC
Message Authentication Code & HMACKrishna Gehlot This document discusses message authentication codes (MACs). It explains that MACs use a shared symmetric key to authenticate messages, ensuring integrity and validating the sender. The document outlines the MAC generation and verification process, and notes that MACs provide authentication but not encryption. It then describes HMAC specifically, which applies a cryptographic hash function to the message and key to generate the MAC. The key steps of the HMAC process are detailed.
Cryptography and Information Security
Cryptography and Information SecurityDr Naim R Kidwai The presentation by Dr. Naim R. Kidwai discusses the critical role of cryptography in protecting information in the digital era, emphasizing concepts such as encryption, decryption, and key management. It highlights the essential goals of cryptography including authentication, confidentiality, data integrity, and non-repudiation, and provides examples of historical ciphers and modern techniques like symmetric and asymmetric key cryptography. Additionally, the document addresses common threats to information security and the importance of key size in determining the security of encryption methods.
Hash function
Hash function Salman Memon A hash function compresses input data into a shorter, fixed-length output known as a hash value, often used for file integrity checks, password encryption, and data verification. It serves as a digital fingerprint, making it nearly impossible to alter the original data without changing the hash. Various hash functions exist, including MD5, SHA, and HMAC, each with specific applications and characteristics.
Confusion and Diffusion.pptx
Confusion and Diffusion.pptxbcanawakadalcollege According to Claude Shannon, confusion and diffusion are two key properties for building strong encryption algorithms. Confusion obscures the relationship between the ciphertext and key by having each ciphertext bit depend on multiple key bits. Diffusion spreads the influence of each plaintext symbol over many ciphertext symbols. Modern block ciphers use repeated rounds of confusion and diffusion operations to build strong encryption.
Cryptography and Network Security William Stallings Lawrie Brown
Cryptography and Network Security William Stallings Lawrie BrownInformation Security Awareness Group Block ciphers like DES encrypt data in blocks and are based on the Feistel cipher structure. DES encrypts 64-bit blocks using a 56-bit key and 16 rounds of encryption. Modern cryptanalysis techniques like differential and linear cryptanalysis use statistical analysis to reveal weaknesses in block ciphers, though DES remains relatively secure against these attacks. Careful design of block ciphers, including aspects like non-linear substitution boxes and complex key scheduling, aims to provide security against cryptanalysis.
Key aggregate searchable encryption (kase) for group data sharing via cloud s...
Key aggregate searchable encryption (kase) for group data sharing via cloud s...CloudTechnologies This document discusses a key-aggregate cryptosystem designed for secure and scalable data sharing in cloud storage, which allows for the delegation of decryption rights using compact aggregate keys. It highlights the limitations of existing systems regarding data confidentiality in shared-tenancy environments and presents a more efficient public-key encryption scheme. Additionally, the document outlines various implementation modules, including searchable encryption and access control, addressing concerns about cloud data privacy and storage.
KEY-AGGREGATE SEARCHABLE ENCRYPTION (KASE) FOR GROUP DATA SHARING VIA CLOUD ...
KEY-AGGREGATE SEARCHABLE ENCRYPTION (KASE) FOR GROUP DATA SHARING VIA CLOUD ...Nexgen Technology The document introduces key-aggregate searchable encryption (KASE) for efficient and secure group data sharing in cloud storage, addressing the challenges of key and trapdoor management. KASE allows a data owner to share a large number of encrypted documents using a single aggregate key, enabling authorized users to search these documents with just one trapdoor. The proposed system demonstrates both security and practical efficiency, offering a solution to the complexities of traditional encryption methods in multi-user scenarios.
More Related Content
What's hot (20)
Encryption And Decryption Using AES Algorithm
Encryption And Decryption Using AES AlgorithmAhmed Raza Shaikh The document discusses encryption and decryption, emphasizing their importance in securing sensitive data. It focuses on the Advanced Encryption Standard (AES), a symmetric block cipher used to protect classified information, highlighting its three variants (AES-128, AES-192, AES-256) and the uniformity of key lengths for data protection. Additionally, it describes a project that employs AES to encrypt and decrypt text files using Java code, ensuring secure communication between parties.
Hash Function
Hash Functionstalin rijal A hash function maps data of arbitrary size to a fixed size value called a hash. Common hash functions include MD5 and SHA, with MD5 producing a 128-bit hash. While hashes were once used to securely store passwords, MD5 is now considered cryptographically broken due to collisions being found in its compression function. One-way signatures allow multiple users to generate linked signatures on the same message in a verifiable chain.
MD5 ALGORITHM.pptx
MD5 ALGORITHM.pptxRajapriya82 The MD5 algorithm is a cryptographic hash function that generates a 128-bit digest from a message of any length. It works by first padding the message to a length that is a multiple of 512 bits, then appending the message length. It initializes buffers and processes the message in 512-bit blocks using four rounds of 16 operations each, applying different functions to update the buffers. The final buffer values become the MD5 digest. It is commonly used to verify file integrity but is now considered insecure due to possible hash collisions.
Transport Layer Security (TLS)
Transport Layer Security (TLS)Arun Shukla Transport Layer Security (TLS) is a protocol that ensures privacy and security between communicating applications on the internet, succeeding the older Secure Sockets Layer (SSL). The TLS protocol consists of a handshake mechanism for authentication and key exchange, and a record protocol for securing application data. It allows for encrypted communication by negotiating cipher suites and generating session keys, thereby preventing eavesdropping and tampering.
Principles of public key cryptography and its Uses
Principles of public key cryptography and its UsesMohsin Ali This document discusses the principles of public key cryptography. It begins by defining asymmetric encryption and how it uses a public key and private key instead of a single shared key. It then discusses key concepts like digital certificates and public key infrastructure. The document also provides examples of how public key cryptography can be used, including the RSA algorithm and key distribution methods like public key directories and certificates. It explains how public key cryptography solves the key distribution problem present in symmetric encryption.
Cryptography
CryptographyDarshini Parikh Cryptography is the practice and study of securing communication through techniques like encryption. It has evolved through manual, mechanical, and modern eras using computers. Cryptography aims to achieve goals like authentication, confidentiality, integrity, and non-repudiation. Common attacks include brute force, chosen plaintext, and differential power analysis. Symmetric cryptography uses a shared key while asymmetric uses public/private key pairs. Digital signatures and watermarks can authenticate documents. DRM and watermarks control digital content distribution.
DES (Data Encryption Standard) pressentation
DES (Data Encryption Standard) pressentationsarhadisoftengg This document discusses data encryption methods. It defines encryption as hiding information so it can only be accessed by those with the key. There are two main types: symmetric encryption uses one key, while asymmetric encryption uses two different but related keys. Encryption works by scrambling data using techniques like transposition, which rearranges the order, and substitution, which replaces parts with other values. The document specifically describes the Data Encryption Standard (DES) algorithm and the public key cryptosystem, which introduced the innovative approach of using different keys for encryption and decryption.
Key management and distribution
Key management and distributionRiya Choudhary Key management is the set of techniques and procedures for establishing and maintaining secure key relationships between parties. It involves generating, distributing, storing, updating, and revoking cryptographic keys. The objectives of key management are to maintain secure keying material and relationships to counter relevant threats like key compromise, in accordance with a security policy. Techniques include symmetric and public-key encryption, key hierarchies, certificates, and life cycle processes around user registration and key installation, update, and destruction.
CS6701 CRYPTOGRAPHY AND NETWORK SECURITY
CS6701 CRYPTOGRAPHY AND NETWORK SECURITYKathirvel Ayyaswamy The document outlines the concepts and mechanisms of email, IP, and web security, focusing on email security services like confidentiality, authentication, and non-repudiation, as well as attacks like phishing. It discusses encryption methods and protocols such as PGP and S/MIME for secure communications, and details the complex framework of IP security (IPsec) covering its architecture, operations, and key management. Additionally, the document describes SSL/TLS for web security, emphasizing the importance of these security measures in protecting information across networks.
Encryption
Encryptionkeith dias The document provides information about encryption and decryption techniques. It defines encryption as converting plaintext into ciphertext and decryption as converting ciphertext back to plaintext. It discusses symmetric encryption which uses the same key for encryption and decryption, and asymmetric encryption which uses public/private key pairs. Specific symmetric algorithms like DES and AES are covered as well as the asymmetric RSA algorithm. Different block cipher modes of operation like ECB, CBC, CFB and OFB are also summarized.
Hash function
Hash functionHarry Potter The document discusses hash functions and message authentication codes (MACs). It begins by defining hash functions and MACs, noting that hash functions generate a fingerprint for a message without a key while MACs use a keyed hash function. It then covers security requirements for hash functions like one-wayness and collision resistance. Popular hash functions are described like MD5, SHA-1, and the SHA-2 family. Constructions for hash functions based on block ciphers and iterated hash functions are also outlined. The document concludes by comparing hash functions and MACs and describing common MAC constructions.
Message authentication
Message authenticationCAS The document discusses computer security focusing on message authentication, highlighting the requirements for message integrity and sender validation. It covers methods such as symmetric and public-key encryption, hash functions, message authentication codes (MAC), and HMAC, explaining their roles in ensuring message security against various attacks. The content serves as an outline for effective communication protocol management in IT, emphasizing the importance of confidentiality and authentication mechanisms.
Public key Infrastructure (PKI)
Public key Infrastructure (PKI)Venkatesh Jambulingam The document discusses Public Key Infrastructure (PKI), highlighting its role in secure online transactions through the use of digital certificates, encryption methods, and trust services. It explains the components of PKI, including registration and certificate authorities, as well as digital signature processes and certificate-based authentication methods. Overall, the content emphasizes ensuring secure communication and verifying identities in the digital realm.
Diffie hellman key exchange algorithm
Diffie hellman key exchange algorithmSunita Kharayat The document explains the Diffie-Hellman key exchange, a foundational method for securely sharing cryptographic keys over a public channel, introduced by Whitfield Diffie and Martin Hellman in 1976. It outlines the algorithm's mechanics, including the use of prime numbers and primitive roots, and discusses potential vulnerabilities, such as the man-in-the-middle attack. Additionally, it presents alternative solutions for secure communication, such as the key distribution center (KDC) while highlighting the challenges associated with replay attacks.
Hash Function
Hash Function ssuserdfb2da This document discusses cryptographic hash functions including their applications in message authentication and digital signatures. It describes the requirements for hash functions to be secure including resistance to brute force attacks and cryptanalysis. The document outlines some simple hash functions and provides details on the Secure Hash Algorithm (SHA) family of cryptographic hash functions used in standards like SHA-512 which operates on 1024-bit blocks through 80 rounds. It also mentions NIST's selection of the Keccak algorithm as the new SHA-3 standard.
Message Authentication Code & HMAC
Message Authentication Code & HMACKrishna Gehlot This document discusses message authentication codes (MACs). It explains that MACs use a shared symmetric key to authenticate messages, ensuring integrity and validating the sender. The document outlines the MAC generation and verification process, and notes that MACs provide authentication but not encryption. It then describes HMAC specifically, which applies a cryptographic hash function to the message and key to generate the MAC. The key steps of the HMAC process are detailed.
Cryptography and Information Security
Cryptography and Information SecurityDr Naim R Kidwai The presentation by Dr. Naim R. Kidwai discusses the critical role of cryptography in protecting information in the digital era, emphasizing concepts such as encryption, decryption, and key management. It highlights the essential goals of cryptography including authentication, confidentiality, data integrity, and non-repudiation, and provides examples of historical ciphers and modern techniques like symmetric and asymmetric key cryptography. Additionally, the document addresses common threats to information security and the importance of key size in determining the security of encryption methods.
Hash function
Hash function Salman Memon A hash function compresses input data into a shorter, fixed-length output known as a hash value, often used for file integrity checks, password encryption, and data verification. It serves as a digital fingerprint, making it nearly impossible to alter the original data without changing the hash. Various hash functions exist, including MD5, SHA, and HMAC, each with specific applications and characteristics.
Confusion and Diffusion.pptx
Confusion and Diffusion.pptxbcanawakadalcollege According to Claude Shannon, confusion and diffusion are two key properties for building strong encryption algorithms. Confusion obscures the relationship between the ciphertext and key by having each ciphertext bit depend on multiple key bits. Diffusion spreads the influence of each plaintext symbol over many ciphertext symbols. Modern block ciphers use repeated rounds of confusion and diffusion operations to build strong encryption.
Cryptography and Network Security William Stallings Lawrie Brown
Cryptography and Network Security William Stallings Lawrie BrownInformation Security Awareness Group Block ciphers like DES encrypt data in blocks and are based on the Feistel cipher structure. DES encrypts 64-bit blocks using a 56-bit key and 16 rounds of encryption. Modern cryptanalysis techniques like differential and linear cryptanalysis use statistical analysis to reveal weaknesses in block ciphers, though DES remains relatively secure against these attacks. Careful design of block ciphers, including aspects like non-linear substitution boxes and complex key scheduling, aims to provide security against cryptanalysis.
Cryptography and Network Security William Stallings Lawrie Brown
Cryptography and Network Security William Stallings Lawrie BrownInformation Security Awareness Group
Similar to Design of Secure Hash Algorithm(SHA) (20)
Key aggregate searchable encryption (kase) for group data sharing via cloud s...
Key aggregate searchable encryption (kase) for group data sharing via cloud s...CloudTechnologies This document discusses a key-aggregate cryptosystem designed for secure and scalable data sharing in cloud storage, which allows for the delegation of decryption rights using compact aggregate keys. It highlights the limitations of existing systems regarding data confidentiality in shared-tenancy environments and presents a more efficient public-key encryption scheme. Additionally, the document outlines various implementation modules, including searchable encryption and access control, addressing concerns about cloud data privacy and storage.
KEY-AGGREGATE SEARCHABLE ENCRYPTION (KASE) FOR GROUP DATA SHARING VIA CLOUD ...
KEY-AGGREGATE SEARCHABLE ENCRYPTION (KASE) FOR GROUP DATA SHARING VIA CLOUD ...Nexgen Technology The document introduces key-aggregate searchable encryption (KASE) for efficient and secure group data sharing in cloud storage, addressing the challenges of key and trapdoor management. KASE allows a data owner to share a large number of encrypted documents using a single aggregate key, enabling authorized users to search these documents with just one trapdoor. The proposed system demonstrates both security and practical efficiency, offering a solution to the complexities of traditional encryption methods in multi-user scenarios.
M021201092098
M021201092098theijes The document presents a research paper evaluating a proposed symmetric key encryption algorithm aimed at improving database security through enhanced throughput and performance compared to existing methods like AES. It discusses the design criteria, implementation details, and provides benchmarks illustrating the efficiency of the new algorithm. The proposed algorithm demonstrates better throughput results while ensuring security, making it suitable for practical data encryption in database management.
A new algorithm for implementing message authentication and integrity in soft...
A new algorithm for implementing message authentication and integrity in soft...TELKOMNIKA JOURNAL This document presents a new algorithm for message authentication and integrity in software applications, focusing on a one-way defragmentation approach that improves security over existing methods. It discusses the importance of validating data in insecure communication channels and provides insights into cryptographic techniques, including hash functions and encryption systems. The proposed hash algorithm aims to enhance security features while ensuring computational efficiency for various applications.
Blockchain Based Decentralized Cloud System
Blockchain Based Decentralized Cloud SystemDhruvdoshi25071999 This document proposes a decentralized cloud storage system using blockchain technology and cryptocurrency payments. It describes a prototype that divides files into fragments stored across multiple peer nodes to improve security, availability and performance over centralized cloud storage. Access control is provided through attribute-based encryption without a centralized authority. Payments between users and peer nodes hosting storage are handled through a custom cryptocurrency implemented with Ethereum smart contracts and the ERC-20 standard. The system aims to provide transparent, redundant and censorship-resistant cloud storage without high upfront costs through a decentralized peer-to-peer network model.
Security in Manets using Cryptography Algorithms
Security in Manets using Cryptography AlgorithmsIRJET Journal This document discusses security in mobile ad hoc networks (MANETs) using cryptography algorithms. It proposes a novel approach for effective key management and prevention of malicious nodes in MANETs. The approach incorporates security to the routing protocol using traditional SHA algorithm along with symmetric (AES) and asymmetric (RSA) key encryption methods. It analyzes the performance of the proposed algorithms by comparing the time taken to transfer data, communication overheads, and battery consumption. The results show that using AES with SHA provides better performance than using RSA with SHA, as RSA consumption more time and battery due to its large prime number calculations and operations.
Comparative Analysis of Cryptographic Algorithms and Advanced Cryptographic A...
Comparative Analysis of Cryptographic Algorithms and Advanced Cryptographic A...editor1knowledgecuddle This document presents a comparative analysis of various cryptographic algorithms, including AES, DES, RSA, and Blowfish, focusing on their effectiveness in securing data in network communication. It emphasizes the importance of both symmetric and asymmetric key algorithms, introducing enhanced encryption techniques such as the Byte-Rotation Encryption Algorithm and a fuzzy logic-based advanced encryption algorithm. The research aims to improve both data security and processing efficiency in encryption methods.
Key aggregate cryptosystem for scalable data sharing in cloud storage
Key aggregate cryptosystem for scalable data sharing in cloud storage Adz91 Digital Ads Pvt Ltd This document discusses a key-aggregate cryptosystem designed for scalable data sharing in cloud storage, allowing for secure and efficient delegation of decryption rights. It introduces a method for creating compact aggregate keys, enabling flexible access while maintaining the confidentiality of other encrypted files. The paper emphasizes improvements over existing schemes by incorporating verifiability in outsourced decryption without relying on assumptions like random oracles.
Documenting Software Architectural Component and Connector with UML 2
Documenting Software Architectural Component and Connector with UML 2editor1knowledgecuddle This document discusses a digital signature scheme based on hash functions, highlighting its importance in ensuring the authenticity and integrity of electronic communications. It reviews public key encryption methods, compares hashing algorithms like MD5 and SHA-2, and analyzes their performance and security implications. The study concludes that digital signatures provide reliable verification mechanisms and emphasizes the significance of secure hash functions in the digital signature processes.
Implementation of De-Duplication Algorithm
Implementation of De-Duplication AlgorithmIRJET Journal The document describes an implementation of a data de-duplication algorithm using convergent encryption. It discusses how data de-duplication works to reduce storage usage by identifying and removing duplicate copies of data. Convergent encryption is used, which generates the same encrypted form of a file from the original file's hash, allowing duplicate encrypted files to be de-duplicated while preserving privacy. The algorithm divides files into blocks, generates hashes for each block, and encrypts the file blocks using the hashes as keys. When a file is uploaded, its hash is checked against existing hashes to identify duplicates, with duplicates replaced by pointers to the stored copy. This allows efficient de-duplication while encrypting data for privacy and security when stored
Efficient Data Mining Of Association Rules in Horizontally Distributed Databases
Efficient Data Mining Of Association Rules in Horizontally Distributed Databasesijircee This document proposes a protocol to securely mine association rules from horizontally distributed databases in a privacy-preserving manner. The key aspects of the protocol are:
1) It uses a novel secure multi-party protocol to compute the union of private subsets held by different players, improving on prior work by avoiding commutative encryption and oblivious transfer.
2) It includes a protocol to test if an element held by one player is contained within a private subset held by another player.
3) Experimental results show the protocol has significantly lower communication and computation costs than prior work, while still protecting individual player's privacy beyond just the final mining results.
Introduction to Blockchain
Introduction to BlockchainHamzamohammed70 This document provides an overview of blockchain technology, focusing on key components such as merkle trees, transaction types, and their implications for security and efficiency. It discusses how blockchain's immutability and decentralized nature facilitate trust and transparency, while also highlighting the various data types involved in blockchain operations. The document concludes by identifying research challenges and opportunities in blockchain data analysis, underscoring its significance for future innovations in the field.
Key aggregate cryptosystem for scalable data sharing in cloud
Key aggregate cryptosystem for scalable data sharing in cloudMeka Subramanyam This document presents a proposed system for secure and flexible data sharing in cloud storage. It describes using new public-key cryptosystems that can aggregate any set of secret keys into a constant-size ciphertext. This allows flexible sharing of encrypted data through an aggregate key that decrypts multiple ciphertexts without increasing in size. The system architecture includes setup, encryption, key generation, and decryption phases. The proposed system aims to address limitations in existing approaches regarding key sizes and flexibility of data access delegation.
Key aggregate cryptosystem for scalable data sharing in cloud storage
Key aggregate cryptosystem for scalable data sharing in cloud storageShakas Technologies The document presents a new public-key cryptosystem for scalable and secure data sharing in cloud storage, which allows for efficient delegation of decryption rights through a compact aggregate key. It introduces an attribute-based encryption (ABE) model with verifiable outsourced decryption, addressing the challenge of transformation correctness while eliminating reliance on random oracles. The proposed system enhances the efficiency of decryption operations, making it suitable for resource-limited devices, thereby improving user data privacy in cloud environments.
REU Group 2 - Paper
REU Group 2 - PaperScott Payne This document discusses research into protocols that enable range queries over encrypted data stored in the cloud. It summarizes implementations of secure comparison (SC) and secure bit decomposition (SBD) using both secret sharing and Paillier encryption schemes. For secret sharing, SC relies on secure multiplication and prefix-OR operations. SBD decomposes values into encrypted bits. For Paillier, SC and SBD use homomorphic properties to compute comparisons and bitwise representations without revealing data. The goal is to verify accuracy of these protocols and compare efficiency of secret sharing versus Paillier encryption for supporting range queries over encrypted data.
iaetsd Secured multiple keyword ranked search over encrypted databases
iaetsd Secured multiple keyword ranked search over encrypted databasesIaetsd Iaetsd This document proposes a Robust Key-Aggregate Cryptosystem (RKAC) that allows flexible and efficient assignment of decryption rights for encrypted data stored in cloud storage. The RKAC produces constant-sized ciphertexts such that a constant-sized aggregate decryption key can decrypt any subset of ciphertexts. This allows the data owner to share access to selected encrypted files by sending a single small aggregate key to authorized users, without decrypting the files themselves or distributing individual keys. The RKAC is described as providing a secure and flexible method for sharing encrypted data stored in the cloud.
A Crypto-System with Embedded Error Control for Secure and Reliable Communica...
A Crypto-System with Embedded Error Control for Secure and Reliable Communica...CSCJournals The paper presents a novel crypto-system with embedded error control (CSEEC) that integrates data security and reliability through a new symmetric encryption algorithm and forward error correction codes (FEC). This system enhances communication efficiency by enabling simultaneous encryption and encoding, catering to resource-constrained nodes in noisy environments. CSEEC allows users to adjust their priorities between security and reliability, achieving optimal communication quality based on application needs.
B03302007012
B03302007012theijes This paper provides a comparative study of various symmetric encryption techniques suitable for mobile data caching in mobile ad-hoc networks, evaluating algorithms such as AES, DES, 3DES, Blowfish, RC2, and RC6 based on factors like block size, key size, and speed. The research highlights the importance of energy consumption in relation to encryption performance and introduces the 'battery gap' issue faced by mobile devices. It concludes that Blowfish exhibits the best performance in terms of efficiency and power usage, followed by RC6, while emphasizing the effectiveness and adaptability of RC6 for contemporary applications.
PERFORMANCE ANALYSIS OF SHA-2 AND SHA-3 FINALISTS
PERFORMANCE ANALYSIS OF SHA-2 AND SHA-3 FINALISTSijcisjournal The document analyzes the performance of SHA-2 and the finalists of SHA-3, highlighting that two SHA-3 finalists, Skein and Blake, perform comparably to SHA-2. NIST's SHA-3 competition aimed to create a secure and efficient hash function, with Keccak emerging as the winner, showing improved security features over SHA-2. Empirical evaluations reveal that, while SHA-2 performs well, Skein consistently outperformed others in various input sizes, with SHA-2 showing the best performance in larger inputs.
PERFORMANCE ANALYSIS OF SHA-2 AND SHA-3 FINALISTS
PERFORMANCE ANALYSIS OF SHA-2 AND SHA-3 FINALISTSijcisjournal This document analyzes the performance of SHA-2 and SHA-3 finalists using cycles per byte as a metric, highlighting that SKIN and BLAKE from the SHA-3 finalists perform comparably to SHA-2. The evaluation emphasizes the importance of security, performance, and cost, with SHA-3 designed to provide a robust alternative to SHA-2. Implementations and tests were conducted in Java on various systems, revealing differing performance results based on input size and algorithm used.
Comparative Analysis of Cryptographic Algorithms and Advanced Cryptographic A...
Comparative Analysis of Cryptographic Algorithms and Advanced Cryptographic A...editor1knowledgecuddle
Ad
Recently uploaded (20)
How to Manage & Create a New Department in Odoo 18 Employee
How to Manage & Create a New Department in Odoo 18 EmployeeCeline George In Odoo 18's Employee module, organizing your workforce into departments enhances management and reporting efficiency. Departments are a crucial organizational unit within the Employee module.
BUSINESS QUIZ PRELIMS | QUIZ CLUB OF PSGCAS | 9 SEPTEMBER 2024
BUSINESS QUIZ PRELIMS | QUIZ CLUB OF PSGCAS | 9 SEPTEMBER 2024Quiz Club of PSG College of Arts & Science THE QUIZ CLUB OF PSGCAS BRINGS T0 YOU A FUN-FILLED, SEAT EDGE BUSINESS QUIZ
DIVE INTO THE PRELIMS OF BIZCOM 2024
QM: GOWTHAM S
BCom (2022-25)
THE QUIZ CLUB OF PSGCAS
Overview of Employee in Odoo 18 - Odoo Slides
Overview of Employee in Odoo 18 - Odoo SlidesCeline George The employee module is a core component of the HR workspace that helps the business to get the employee activities and details. This would also allow you to get the employee details by acting as a centralized system and accessing, updating, and managing all the other employee data.
ROLE PLAY: FIRST AID -CPR & RECOVERY POSITION.pptx
ROLE PLAY: FIRST AID -CPR & RECOVERY POSITION.pptxBelicia R.S Role play : First Aid- CPR, Recovery position and Hand hygiene.
Scene 1: Three friends are shopping in a mall
Scene 2: One of the friend becomes victim to electric shock.
Scene 3: Arrival of a first aider
Steps:
Safety First
Evaluate the victim‘s condition
Call for help
Perform CPR- Secure an open airway, Chest compression, Recuse breaths.
Put the victim in Recovery position if unconscious and breathing normally.
Chalukyas of Gujrat, Solanki Dynasty NEP.pptx
Chalukyas of Gujrat, Solanki Dynasty NEP.pptxDr. Ravi Shankar Arya Mahila P. G. College, Banaras Hindu University, Varanasi, India. This presentation has been made keeping in mind the students of undergraduate and postgraduate level. In this slide try to present the brief history of Chaulukyas of Gujrat up to Kumarpala To keep the facts in a natural form and to display the material in more detail, the help of various books, websites and online medium has been taken. Whatever medium the material or facts have been taken from, an attempt has been made by the presenter to give their reference at the end.
Chaulukya or Solanki was one of the Rajputs born from Agnikul. In the Vadnagar inscription, the origin of this dynasty is told from Brahma's Chauluk or Kamandalu. They ruled in Gujarat from the latter half of the tenth century to the beginning of the thirteenth century. Their capital was in Anahilwad. It is not certain whether it had any relation with the Chalukya dynasty of the south or not. It is worth mentioning that the name of the dynasty of the south was 'Chaluky' while the dynasty of Gujarat has been called 'Chaulukya'. The rulers of this dynasty were the supporters and patrons of Jainism.
LDMMIA Spring Ending Guest Grad Student News
LDMMIA Spring Ending Guest Grad Student NewsLDM & Mia eStudios Available Sun June 8th, for Weekend June 14th/15th.
Timeless for Summer 25.
Our libraries do host classes for a year plus in most shops. Timelines do vary.
See also our Workshops 8, 9, and 2 Grad/Guest Updates.
Workshop 9 was uploaded early also for Weekend June 14th/15th.
Reiki Yoga Level 1 - Practitioner Studies. For our June Schedules
I luv the concept of effortless learning. My Background includes traditional & Distant Education. My Fav classes were online. A few on Campus recent years.
So, for LDMMIA I believe in Self-Help, Self-Care, Self-Serve lol. “How can my followers/readers privately attend courses?” So this season, I do want to expand our new Merch Shop. This includes digital production like no other - Wow. More Updates this Mo lol.
Merch Host: teespring.com
Final Sketch Designs for poster production.pptx
Final Sketch Designs for poster production.pptxbobby205207 Final Sketch Designs for poster production.
Paper 108 | Thoreau’s Influence on Gandhi: The Evolution of Civil Disobedience
Paper 108 | Thoreau’s Influence on Gandhi: The Evolution of Civil DisobedienceRajdeep Bavaliya Dive into the powerful journey from Thoreau’s 19th‑century essay to Gandhi’s mass movement, and discover how one man’s moral stand became the backbone of nonviolent resistance worldwide. Learn how conscience met strategy to spark revolutions, and why their legacy still inspires today’s social justice warriors. Uncover the evolution of civil disobedience. Don’t forget to like, share, and follow for more deep dives into the ideas that changed the world.
M.A. Sem - 2 | Presentation
Presentation Season - 2
Paper - 108: The American Literature
Submitted Date: April 2, 2025
Paper Name: The American Literature
Topic: Thoreau’s Influence on Gandhi: The Evolution of Civil Disobedience
[Please copy the link and paste it into any web browser to access the content.]
Video Link: https://youtu.be/HXeq6utg7iQ
For a more in-depth discussion of this presentation, please visit the full blog post at the following link: https://rajdeepbavaliya2.blogspot.com/2025/04/thoreau-s-influence-on-gandhi-the-evolution-of-civil-disobedience.html
Please visit this blog to explore additional presentations from this season:
Hashtags:
#CivilDisobedience #ThoreauToGandhi #NonviolentResistance #Satyagraha #Transcendentalism #SocialJustice #HistoryUncovered #GandhiLegacy #ThoreauInfluence #PeacefulProtest
Keyword Tags:
civil disobedience, Thoreau, Gandhi, Satyagraha, nonviolent protest, transcendentalism, moral resistance, Gandhi Thoreau connection, social change, political philosophy
Black and White Illustrative Group Project Presentation.pdf (1).pdf
Black and White Illustrative Group Project Presentation.pdf (1).pdfAnnasofiaUrsini mmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmm
Vikas Bansal Himachal Pradesh: A Visionary Transforming Himachal’s Educationa...
Vikas Bansal Himachal Pradesh: A Visionary Transforming Himachal’s Educationa...Himalayan Group of Professional Institutions (HGPI) Himachal Pradesh’s beautiful hills have long faced a challenge: limited access to quality education and career opportunities for students in remote towns and villages. Many young people had to leave their homes in search of better learning and growth, creating a gap between talent and opportunity.
Vikas Bansal, a visionary leader, decided to change this by bringing education directly to the heart of the Himalayas. He founded the Himalayan Group of Professional Institutions, offering courses in engineering, management, pharmacy, law, and more. These institutions are more than just schools—they are centers of hope and transformation.
By introducing digital classrooms, smart labs, and practical workshops, Vikas ensures that students receive modern, high-quality education without needing to leave their hometowns. His skill development programs prepare youth for real-world careers by teaching technical and leadership skills, with strong industry partnerships and hands-on training.
Vikas also focuses on inclusivity, providing scholarships, career counseling, and support to underprivileged and first-generation learners. His quiet but impactful leadership is turning Himachal Pradesh into a knowledge hub, empowering a new generation to build a brighter future right in their own hills.
Exploring Ocean Floor Features for Middle School
Exploring Ocean Floor Features for Middle SchoolMarie This 16 slide science reader is all about ocean floor features. It was made to use with middle school students.
You can download the PDF at thehomeschooldaily.com
Thanks! Marie
Battle of Bookworms 2025 - U25 Literature Quiz by Pragya
Battle of Bookworms 2025 - U25 Literature Quiz by Pragya Pragya - UEM Kolkata Quiz Club Battle of Bookworms is a literature quiz organized by Pragya, UEM Kolkata, as part of their cultural fest Ecstasia. Curated by quizmasters Drisana Bhattacharyya, Argha Saha, and Aniket Adhikari, the quiz was a dynamic mix of classical literature, modern writing, mythology, regional texts, and experimental literary forms. It began with a 20-question prelim round where ‘star questions’ played a key tie-breaking role. The top 8 teams moved into advanced rounds, where they faced audio-visual challenges, pounce/bounce formats, immunity tokens, and theme-based risk-reward questions. From Orwell and Hemingway to Tagore and Sarala Das, the quiz traversed a global and Indian literary landscape. Unique rounds explored slipstream fiction, constrained writing, adaptations, and true crime literature. It included signature IDs, character identifications, and open-pounce selections. Questions were crafted to test contextual understanding, narrative knowledge, and authorial intent, making the quiz both intellectually rewarding and culturally rich. Battle of Bookworms proved literature quizzes can be insightful, creative, and deeply enjoyable for all.
Introduction to Generative AI and Copilot.pdf
Introduction to Generative AI and Copilot.pdfTechSoup In this engaging and insightful two-part webinar series, where we will dive into the essentials of generative AI, address key AI concerns, and demonstrate how nonprofits can benefit from using Microsoft’s AI assistant, Copilot, to achieve their goals.
This event series to help nonprofits obtain Copilot skills is made possible by generous support from Microsoft.
PEST OF WHEAT SORGHUM BAJRA and MINOR MILLETS.pptx
PEST OF WHEAT SORGHUM BAJRA and MINOR MILLETS.pptxArshad Shaikh Wheat, sorghum, and bajra (pearl millet) are susceptible to various pests that can significantly impact crop yields. Common pests include aphids, stem borers, shoot flies, and armyworms. Aphids feed on plant sap, weakening the plants, while stem borers and shoot flies damage the stems and shoots, leading to dead hearts and reduced growth. Armyworms, on the other hand, are voracious feeders that can cause extensive defoliation and grain damage. Effective management strategies, including resistant varieties, cultural practices, and targeted pesticide applications, are essential to mitigate pest damage and ensure healthy crop production.
How to Create an Event in Odoo 18 - Odoo 18 Slides
How to Create an Event in Odoo 18 - Odoo 18 SlidesCeline George Creating an event in Odoo 18 is a straightforward process that allows you to manage various aspects of your event efficiently.
Odoo 18 Events Module is a powerful tool for organizing and managing events of all sizes, from conferences and workshops to webinars and meetups.
LDMMIA Free Reiki Yoga S9 Grad Level Intuition II
LDMMIA Free Reiki Yoga S9 Grad Level Intuition IILDM & Mia eStudios Completed Sunday 6/8. For Weekend 6/14 & 15th. (Fathers Day Weekend US.) These workshops are also timeless for future students TY. No admissions needed.
A 9th FREE WORKSHOP
Reiki - Yoga
“Intuition-II, The Chakras”
Your Attendance is valued.
We hit over 5k views for Spring Workshops and Updates-TY.
Thank you for attending our workshops.
If you are new, do welcome.
Grad Students: I am planning a Reiki-Yoga Master Course (As a package). I’m Fusing both together.
This will include the foundation of each practice. Our Free Workshops can be used with any Reiki Yoga training package. Traditional Reiki does host rules and ethics. Its silent and within the JP Culture/Area/Training/Word of Mouth. It allows remote healing but there’s limits As practitioners and masters, we are not allowed to share certain secrets/tools. Some content is designed only for “Masters”. Some yoga are similar like the Kriya Yoga-Church (Vowed Lessons). We will review both Reiki and Yoga (Master tools) in the Course upcoming.
S9/This Week’s Focus:
* A continuation of Intuition-2 Development. We will review the Chakra System - Our temple. A misguided, misused situation lol. This will also serve Attunement later.
Thx for tuning in. Your time investment is valued. I do select topics related to our timeline and community. For those seeking upgrades or Reiki Levels. Stay tuned for our June packages. It’s for self employed/Practitioners/Coaches…
Review & Topics:
* Reiki Is Japanese Energy Healing used Globally.
* Yoga is over 5k years old from India. It hosts many styles, teacher versions, and it’s Mainstream now vs decades ago.
* Anything of the Holistic, Wellness Department can be fused together. My origins are Alternative, Complementary Medicine. In short, I call this ND. I am also a metaphysician. I learnt during the 90s New Age Era. I forget we just hit another wavy. It’s GenZ word of Mouth, their New Age Era. WHOA, History Repeats lol. We are fusing together.
* So, most of you have experienced your Spiritual Awakening. However; The journey wont be perfect. There will be some roller coaster events. The perks are: We are in a faster Spiritual Zone than the 90s. There’s more support and information available.
(See Presentation for all sections, THX AGAIN.)
BUSINESS QUIZ PRELIMS | QUIZ CLUB OF PSGCAS | 9 SEPTEMBER 2024
BUSINESS QUIZ PRELIMS | QUIZ CLUB OF PSGCAS | 9 SEPTEMBER 2024Quiz Club of PSG College of Arts & Science
Chalukyas of Gujrat, Solanki Dynasty NEP.pptx
Chalukyas of Gujrat, Solanki Dynasty NEP.pptxDr. Ravi Shankar Arya Mahila P. G. College, Banaras Hindu University, Varanasi, India.
Vikas Bansal Himachal Pradesh: A Visionary Transforming Himachal’s Educationa...
Vikas Bansal Himachal Pradesh: A Visionary Transforming Himachal’s Educationa...Himalayan Group of Professional Institutions (HGPI)
Ad
Design of Secure Hash Algorithm(SHA)
- 1. DESIGN OF SECURE HASH ALGORITHM Dr.T.M.SARAVANAN Associate Professor, Department of Computer Applications, Kongu Engineering College, Perundurai – 638 060.
- 2. SECURE HASH ALGORITHM Here we will see the design of SHA-256 and SHA-3. Both of these are used in Bitcoin and Ethereum, respectively. 1. Design of SHA-256 SHA-256 has the input message size < 264-bits. Block size is 512- bits, and it has a word size of 32-bits. The output is a 256-bit digest. The compression function processes a 512-bit message block and a 256-bit intermediate hash value. There are two main components of this function: the Compression Function and a Message Schedule. 29-06-2021
- 3. SECURE HASH ALGORITHM The algorithm works as follows, in eight steps: 1. Preprocessing: 1. Padding of the message is used to adjust the length of a block to 512-bits if it is smaller than the required block size of 512-bits. 2. Parsing the message into message blocks, which ensures that the message and its padding is divided into equal blocks of 512- bits. 3. Setting up the initial hash value, which consists of the eight 32-bit words obtained by taking the first 32-bits of the fractional parts of the square roots of the first eight prime numbers. These initial values are randomly chosen to initialize the process, and they provide a level of confidence that no backdoor exists in the algorithm. 29-06-2021
- 4. SECURE HASH ALGORITHM 2. Hash computation: 4. Each message block is then processed in a sequence, and it requires 64 rounds to compute the full hash output. Each round uses slightly different constants to ensure that no two rounds are the same. 5. The message schedule is prepared. 6. Eight working variables are initialized. 7. The intermediate hash value is calculated. 8. Finally, the message is processed, and the output hash is produced: 29-06-2021
- 6. SECURE HASH ALGORITHM In the preceding diagram, a, b, c, d, e, f, g, and h are the registers. Maj and Ch are applied bitwise. Σ0 and Σ1 performs bitwise rotation. Round constants are Wj and Kj, which are added, mod 232. Maj stands for majority , Ch stands for choose or choice. 29-06-2021
- 7. SECURE HASH ALGORITHM 2. Design of SHA-3(Keccak) The structure of SHA-3 is very different from that of SHA-1 and SHA- 2. The key idea behind SHA-3 is based on unkeyed permutations, as opposed to other typical hash function constructions that used keyed permutations. Keccak also does not make use of the Merkle-Damgard transformation that is commonly used to handle arbitrary-length input messages in hash functions. A newer approach called sponge and squeeze construction is used in Keccak. It is a random permutation model. 29-06-2021
- 8. SECURE HASH ALGORITHM 2. Design of SHA-3(Keccak) Different variants of SHA-3 have been standardized, such as SHA-3- 224, SHA-3-256, SHA-3-384, SHA-3-512, SHAKE-128, and SHAKE- 256. SHAKE-128 and SHAKE-256 are Extendable Output Functions (XOFs), which are also standardized by NIST. XOFs allow the output to be extended to any desired length. The following diagram shows the sponge and squeeze model, which is the basis of SHA-3 or Keccak. 29-06-2021
- 10. SECURE HASH ALGORITHM 2. Design of SHA-3(Keccak) Analogous to a sponge, the data is first absorbed into the sponge after applying padding. There it is then changed into a subset of permutation state using XOR, and then the output is squeezed out of the sponge function that represents the transformed state. The rate is the input block size of a sponge function, while capacity determines the general security level. 29-06-2021
- 12. SECURE HASH ALGORITHM Usually, hash functions do not use a key. Nevertheless, if they are used with a key, then they can be used to create another cryptographic construct called MACs. Message Authentication Codes MACs are sometimes called keyed hash functions, and they can be used to provide message integrity and authentication. More specifically, they are used to provide data origin authentication. These are symmetric cryptographic primitives that use a shared key between the sender and the receiver. MACs can be constructed using block ciphers or hash functions. 29-06-2021
- 13. SECURE HASH ALGORITHM With this approach, block ciphers are used in the Cipher Block Chaining (CBC) mode in order to generate a MAC. Any block cipher, for example AES in the CBC mode, can be used. The length of the MAC output is the same as the block length of the block cipher used to generate the MAC. MACs are verified simply by computing the MAC of the message and comparing it to the received MAC. If they are the same, then the message integrity is confirmed; otherwise, the message is considered altered. It should also be noted that MACs work like digital signatures, however they cannot provide non-repudiation service due to their symmetric nature. 29-06-2021
- 14. SECURE HASH ALGORITHM Merkle Trees The concept of Merkle tree was introduced by Ralph Merkle. Merkle trees enable secure and efficient verification of large datasets. A diagram of Merkle tree is shown here. A Merkle tree is a binary tree in which the inputs are first placed at the leaves (node with no children), and then the values of pairs of child nodes are hashed together to produce a value for the parent node (internal node) until a single hash value known as Merkle root is achieved. 29-06-2021
- 16. SECURE HASH ALGORITHM Patricia Trees To understand Patricia trees, you will first be introduced to the concept of a trie. Trie is an efficient information reTrieval data structure. Using Trie, search complexities can be brought to optimal limit (key length). A trie, or a digital tree, is an ordered tree data structure used to store a dataset. Practical Algorithm to Retrieve Information Coded in Alphanumeric (Patricia), also known as Radix tree, is a compact representation of a trie in which a node that is the only child of a parent is merged with its parent. A Merkle-Patricia tree, based on the definitions of Patricia and Merkle, is a tree that has a root node which contains the hash value of the entire data structure. 29-06-2021
- 17. SECURE HASH ALGORITHM Distributed Hash Tables A hash table is a data structure that is used to map keys to values. Internally, a hash function is used to calculate an index into an array of buckets from which the required value can be found. Buckets have records stored in them using a hash key and are organized into a particular order. One can think of a DHT as a data structure where data is spread across various nodes, and nodes are equivalent to buckets in a peer- to-peer network. The following diagram shows how a DHT works. 29-06-2021
- 19. SECURE HASH ALGORITHM Distributed Hash Tables Data is passed through a hash function, which then generates a compact key. This key is then linked with the data (values) on the peer-to-peer network. When users on the network request the data (via the filename), the filename can be hashed again to produce the same key, and any node on the network can then be requested to find the corresponding data. DHT provides decentralization, fault tolerance, and scalability. Another application of hash functions is in digital signatures, where they can be used in combination with asymmetric cryptography. 29-06-2021
- 20. SECURE HASH ALGORITHM Digital Signatures Digital signatures provide a means of associating a message with an entity from which the message has originated. Digital signatures are used to provide data origin authentication and non-repudiation. Digital signatures are used in blockchain where the transactions are digitally signed by senders using their private key before broadcasting the transaction to the network. This digital signing, proves they are the rightful owner of the asset, for example, bitcoins. These transactions are verified again by other nodes on the network to ensure that the funds indeed belong to the node (user) who claims to be the owner. 29-06-2021
- 21. SECURE HASH ALGORITHM Signcryption Signcryption is a public key cryptography primitive that provides all of the functions of a digital signature and encryption. Yuliang Zheng invented signcryption, and it is now an ISO standard, ISO/IEC 29150:2011. Traditionally, sign then encrypt or encrypt then sign schemes are used to provide unforgeability, authentication, and non-repudiation, but with signcryption, all services of digital signatures and encryption are provided at a cost that is less than that of the sign then encrypt scheme. Signcryption enables Cost (signature & encryption) << Cost (signature) + Cost (Encryption) in a single logical step. 29-06-2021
- 22. SECURE HASH ALGORITHM Blind Signatures Blind signatures were introduced by David Chaum in 1982. They are based on public key digital signature schemes, such as RSA. The key idea behind blind signatures is to get the message signed by the signer without actually revealing the message. This is achieved by disguising or blinding the message before signing it, hence the name blind signatures. This blind signature can then be verified against the original message just like a normal digital signature. Blind signatures were introduced as a mechanism to allow the development of digital cash schemes. 29-06-2021