Patent ID: 7725926

Claim:
A method for authentication in a client computer, comprising: obtaining a client base value selected by a user of the client computer for at least a first usage purpose, the first usage purpose comprising generating a one-time password for accessing a web site on a remote computer; incrementing a client integer originally selected by the user for at least a second usage purpose such that the client integer increases in value, the second usage purpose comprising limiting access to an email inbox for spam control; combining the client base value with the client integer to obtain a client combination; hashing the client combination to obtain a client password; and maintaining a stored base value and a stored integer for the user on a remote computer, the stored integer being a previous value of the client integer prior to the client integer being incremented and increased in value; transmitting to the remote computer a request comprising the client password and the client integer; comparing the client integer to the stored integer; if the client integer is lower than or equal to the stored integer, rejecting the request; if the client integer is higher than the stored integer, combining the stored base value with the client integer to obtain a remote combination, hashing the remote combination to obtain a remote password, and if the remote password does not match the client password, rejecting the request; if the remote password matches the client password, authorizing the request, and replacing the stored integer with the client integer, such that the stored integer after being replaced has a higher value than before.