In this paper, the authors present the protection of long lived private key & public key using cryptographic schemes is one of the most important issues for information security. Any cryptographic scheme that reveals private key and public key will soon its security absolutely disintegrates. Public key are used in two different based, i.e. RSA and elliptic curve cryptography both are modular based arithmetic and private key is along random bit string and should be stored securely, some cryptographic are implemented in hardware such as an smart card IC(integrated circuit) needed to store the private key. Unfortunately, the security system in digital signature system, anyone obtains the victim's private key, authenticity and non repudiation can no longer be claimed.