Patent ID: 7895436

Claim:
An authentication system for mutual authentication between a terminal and a server wherein the terminal comprises: a memory means that pre-stores an authentication information P′ for terminal storage; a concatenation means that yields a value P using a specific calculation formula in response to the input of the authentication information P′ read from the memory means and a password entered for authentication; a mask operation means that yields a value Y 1 using a specific calculation formula with the input value P and an internally generated random number, and then sends Y 1 to the server; and a master key generation means that yields a value MK using a specific calculation formula with the input value P, an internally generated random number and a value Y 2 received from a server that comprises: a memory means that pre-stores a password verification data H for server registration; a mask operation means that yields a value Y 2 using a specific calculation formula with the input of the password verification data H read from the memory means and an internally generated random number, and then sends Y 2 to the terminal; and a master key generation means that yields a value MK using a specific calculation formula with the input of the password verification data H, an internally generated random number and the value Y 1 received from the terminal.