Using Client Puzzles to Protect TLS Servers From Denial of Service Attacks

Document Type Expired Internet-Draft (individual)
Author Yoav Nir 
Last updated 2014-11-10 (latest revision 2014-04-30)
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This Internet-Draft is no longer active. A copy of the expired Internet-Draft can be found at


This document proposes a mechanism for mitigating denial of service (DoS) and distributed denial of service (DDoS) attacks on TLS servers. Attackers are limited in their ability to cause resource waste on the server by requiring proof of work by the client before these CPU resources are expended.


Yoav Nir (

(Note: The e-mail addresses provided for the authors of this Internet-Draft may no longer be valid.)