Public-key cryptosystem HIME: high performance modular squaring based public key encryption

摘要

We propose two efficient and provably secure public-key cryptosystems. HIME-1, which is based on the modular squaring, is semantically secure against the adaptive chosen ciphertext attack (IND-CCA2) on the random oracle model under the assumption of the difficulty of the factoring problem. The decryption speed of HIME-1 is faster than that of the elliptic curve cryptosystems. HIME-2, which is based on the Rabin's public key encryption scheme, is also IND-CCA2 on the random oracle model under the assumption of the difficulty of the factoring problem. HIME-2 has a faster speed in both the encryption and the decryption than previous public key schemes, though the decryption speed of HINIE-2 is slower than that of HIME-1.