Y PLACE

CROSSBOW encrypts all data using ChaCha20, one of the most powerful encryption algorithms available. In general, encryption and decryption are expected to slow down transmission speed. However, CROSSBOW experiences no slowdown at all thanks to its sophisticated thread separation and job control design. Encryption and decryption introduce no speed penalty—only a slight increase in CPU usage.

Congestion control stands as a formidable challenge in the realm of protocol design. It necessitates dynamically adjusting the transmission rate by taking into account both the prevailing network conditions and the respective states of the sending and receiving entities. This complex issue has been the subject of extensive research, leading to a wealth of academic literature. From a comprehensive review of these numerous papers, we have identified and chosen a method that is both elegantly simple and demonstrably effective. Our paramount objective is to achieve a stable transmission speed, minimizing any precipitous fluctuations.

Our main product is CROSSBOW. It is a high-speed file transfer software. This program is based on the MKFFT and MKUDP libraries. MKFFT is a library for high-speed file transfer. MKUDP is a reliable communication protocol based on UDP. It supports Windows and macOS operating systems.

Most file transfer programs utilize a client-server approach. The sender uploads the file to a server, and the recipient then downloads it. This method doubles the time required and incurs server maintenance costs. While direct transfer between sender and receiver would be optimal, it presents significant challenges due to issues such as NAT and firewalls. Our product, CROSSBOW, has dedicated considerable effort to overcoming these obstacles. It employs a fundamental P2P (peer-to-peer) architecture, enabling direct file transfers between the sender and receiver. This not only halves the transfer time but also eliminates the need for server expenses. We have integrated numerous advanced technologies to seamlessly navigate NAT and firewalls, ensuring a smooth and hassle-free experience for the user.

Program development is similar to building a clock. It's an intricate object where countless gears mesh and turn. The similarity lies in the fact that if even a single gear malfunctions, the whole system breaks down. There's the frustration when software developed over a long period doesn't work correctly, and then the joy when just a single line of code fixes everything, making it all work perfectly. It's difficult but rewarding, and there's a unique satisfaction in it.

Memory management completely upgraded. Managing and transferring thousands to tens of thousands of files was quite difficult in terms of memory management. Handling a few hundred was easy, but processing tens of thousands simultaneously puts a significant strain on the system. To improve this, we enhanced file session management. We replaced the existing vector-based system with a map-based one, and for objects with delays like file writing, we implemented an async delete function for delayed deletion.

Automatic Recovery   In most cases, when a server or client stops and then restarts, other protocols require user intervention to restore the network connection.   However, MKUDP automatically restores the connection without any user action, even if either the server or client experiences a failure and recovers.

Polished with several AI models MKUDP is a highly reliable communication protocol developed over many years as a replacement for TCP. It was designed with the goals of low latency, stability, automatic recovery, and simplicity. Multiple AI models were used for cross-review, and the improvements suggested during this process were applied. The refinement continued until the AI models had no further recommendations to offer.

Quality is not something to be compromised. Developing a program that simply works is no easy task, but creating one that runs with true reliability, stability, and perfection is far more difficult. Raising a program from a state of basic functionality to one of dependable performance requires an effort beyond imagination. The difference between a masterpiece and a mass-produced product lies in such details. CROSSBOW and MKUDP have been refined to an obsessive level of quality through years of development and continuous improvement.

CROSSBOW is available in two editions: FULL and LITE. The FULL version supports multiple users simultaneously connecting to a single server for file transfers. This enables it to function as a high-speed, encrypted file transfer server. The LITE version allows only one user to connect at a time. A single user can upload or download files to/from the server. Both versions offer identical transfer speeds and encryption capabilities. The only difference is the number of concurrent connections supported.