Fast and Secure Protocol

FASP has built-in security mechanisms that do not affect the transmission speed. The encryption algorithms used are based exclusively on open standards. Some product implementation use secure key exchange and authentication such as SSH. The data is optionally encrypted or decrypted immediately before sending and receiving with the AES-128. To counteract attacks by monitoring the encrypted information during long transfers, the AES is operated in cipher feedback mode with a random, public initialization vector for each block. In addition, an integrity check of each data block takes place, in which case, for example, a man-in-the-middle attack would be noticed. ==Protocol==

FASP's control port is TCP port 22 the same port that SSH uses. For data transfer, it begins at UDP port 33001, which increments with each additional connection thread. The transmission rate is chosen to match and not exceed the available channel bandwidth, and trigger no drops, accounting for all traffic on the channel. By contrast, TCP slowly increases its rate until it sees a packet drop and falls back, interpreting any drop as congestion. On a channel with long delay and frequent packet loss, TCP never approaches the actual bandwidth available. FASP cooperates with TCP flows on the same channel, using up bandwidth TCP leaves unused. ==See also==