Improved Merkle Cryptosystem (IMC)

Merkle Cryptosystem (MC) is the first cryptosystem which introduces general concept of the public key cryptography. In this paper, the authors propose Improved Merkle Cryptosystem (IMC), which has significant security advantages over both MC and a Variant of MC (VMC). In IMC, cryptographic hash functions and a new puzzle structure are used together in order to increase the security of MC and VMC. The key agreement value, which is send as clear text in VMC, is hidden using cryptographic hash function in IMC. Also, in order to increase security of the key agreement value, auxiliary keys are used. Notice that, in IMC, computational advantages of VMC remain unchanged while its security is increased.