Re: Searching for a special challenge&response algorithm

Jan Peter Stotz wrote:
>When a client connects to a server it has to authenticate itself against
>the server. For preventing brute force attacks against this authentication
>(systematic testing) with one client the server creates a challenge which
>has to be solved by the client. For solving the challenge the client needs
>a bit of CPU power which results in a delay of about a second. The server
>only allows an authentication by the client after successfully solving the
>challenge.

You'll find a lot of work on the literature on this subject.
Some key words to aid you in your literature search: "client puzzles",
"hashcash", "proofs of work".
Received on Mon May 1 02:06:11 2006