On security enhancement of long-term private key for the tripartite authenticated key agreement protocol
Masahiro Nomura, Katsuhiro Nakamura · 2008
In this paper, we propose a scheme that enhances the security of long-term private key lIDused in the tripartite authenticated key agreement protocol. In this scheme, we use (H(lIDPmacr)lID)P (H: hash function) instead of lIDP (P: a rational point of the defined elliptic curve over Fp) as a static public key and tauID1, tauID2as two ephemeral private keys. From this, even though the bit length of p (p's security parameter) is more lessened, we can preserve equal security to conventional schemes in respect of the secrecy of the long-term private key.