| 摘要 |
<p>A method of preventing relay attacks between a terminal device and a token device (e.g. smartcard) in an electronic authentication system, comprising: sending first dynamic (random) data from said terminal device to said token device and receiving second random data from said token device at said terminal device; monitoring a timing characteristic relating to a time difference between the exchange of the random data; receiving encrypted data generated by the token device after said monitored exchange has taken place, wherein said encrypted data is cryptographically related to both said first and said second random data (e.g. by encrypting the random data) such that a cryptographic validation process may be used to confirm that said timing characteristic is representative of said token device having validly taken part in the exchange of random data.</p> |
