Three-Way Handshake-Based OTP Using Random Host-Side Keys for Effective Key Transfer in Symmetric Cryptosystems

Abstract

Vernam cipher is said to be one of the most secure cipher systems in use, based on the key size. It is derived from the One-Time Pad (OTP) method. One of the main features of the cipher is that it is completely reversible with the use of XOR operation, with no loss of data. It is independently a symmetric cryptosystem, which needs the key to be transmitted to both ends for effective working. The same case applies for all symmetric ciphers. But the main drawback of symmetric ciphers is that the key has to be transmitted from sender to recipient, over the insecure channel. Even if we try to implement maximum security, the key transmission should be secured as much as possible. Here, we use the power of OTP to implement key transmission in symmetric cryptosystems. The concept is based on an age-old principle of securing parcels, by using two separate locks, and not transferring the keys across. But this involves multiple transactions for sending the same parcel, and the same method can be implemented as a 3-way handshake. The keys at the host can be chosen randomly since they are never transmitted across. The method has been shown to have the strength exceeding Vernam cipher itself. But the drawback is that the method becomes inefficient for large data, since the handshakes involve lot of data transfer.