PUBLIC KEY ENCRYPTION COMMUNICATION METHOD

摘要

PROBLEM TO BE SOLVED: To provide a public key encryption communication technology capable of certifying security. SOLUTION: In a Rabin encryption, a composite number N as the public key is selected as p<d> q (p, q are prime numbers and d is more than 1). A hash function is combined with an OAEP by using uniqueness for decrypting. The security can be certified on conditions of a rapidly decrypting process and difficulty for factoring N into prime numbers. (The security shows strong concealment against an attack of adaptively selecting encrypted texts). The security against the attack of selecting the encrypted texts can be certified and the public key encryption communication technology capable of rapidly processing decryption can be provided. The public key encryption communication technology can also reduce a computational load when a transmitted data is encrypted and decrypted and certify as an IND-CCA2 on a condition of difficulty for computing an inverse function of one-way substitution (e.g. difficulty for factoring into prime numbers).