Patent ID: 8014527

Claim:
A method of reusing a pair of public and private keys, which is performed in a host, the method comprising: determining whether a pair of public and private keys that have already been used in a first encryption process between the host and a second host are still usable in a second encryption process, wherein the pair of public and private keys are determined as being reusable if the second encryption process is between the host and a third host other than the second host; and reusing the pair of public and private keys in the second encryption process if the pair of public and private keys are determined as being reusable, wherein the determining whether the pair of public and private keys are reusable comprises determining whether a number of times the pair of public and private keys have been used exceeds a predetermined maximum number; and determining whether the pair of public and private keys have already been used by the third host unless the number of times the pair of public and private keys have been used exceeds the predetermined maximum number, wherein, the pair of public and private keys are reused in the second encryption process if the pair of public and private keys have not yet been used by the third host.