| 摘要 |
<p>The invention relates to a security token (SIM, SC) which stores secret data (PIN) for authenticating a user, and which comprises means for generating random data (DATA) generating a randomly distorted representation (CAPTCHA) of the random data (DATA), the representation (CAPTCHA) being recognizable by a human being but hard to recognize by a machine, sending the representation (CAPTCHA) to a computing device (MP, PC), receiving data from the computing device (MP, PC), and authenticating the user if the data received matches the secret data (PIN) and the random data (DATA). The invention also relates to a system comprising the above security device and a computing device, as well as a method for improving the security of the authentication of a user based on the above security device.</p> |
