Re: Searching for a special challenge&response algorithm

David Wagner schrieb:

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

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".

Thank you David, these are the keywords I were searching for.