Efficiency increasing method for quantum secure direct communication protocols

Particularly vulnerable spot for violation of information security is a data network, since it is impossible to guarantee the data protection when transferring them through a public environment (Internet, telephone lines, radio). Therefore, the information transmitted on different networks, particularly in need of security and the main way of providing it, is using the cryptographic methods. However, recent research has shown that classical cryptography gives a cause to look for new prospects and it could be quantum cryptography. Among all possible quantum cryptography technologies, quantum secure direct communication (e.g. Ping-Pong protocol) does not use any cryptographic transformations, so there is no key distribution problem and eavesdropping can be detected during transfer, thereby improving information transmitting reliability. In this paper security amplification method for Ping-Pong protocol was proposed. This method uses generated ternary pseudorandom sequence and transformations in Galois field. Accordingly, this could increase the protocol asymptotical security and accelerate its work at least 3 times.