TLS protocol: Secure protocol with Client Puzzles

Client puzzles are commonly proposed as a solution to denial-of-service attacks. We analyzed the TLS protocol and implement Client Puzzles algorithm. We pursued the following objectives: analyze TLS handshake protocol and implement Client Puzzles algorithm using Hash Functions, Diffie-Hellman Base Puzzle Scheme and Threshold Puzzles. The originality of the paper is due to a comparative study of methods used to create the Client Puzzle solution. We also present measurements of execution time when our modified protocol is under attack.