Title: RSA Security's Statement about IPR claimed in draft-ietf-ipsec-properties-00 and draft-jennings-sip-hashcash-00 Received: 30 August 2004 From: Linn, John RSA Security Inc. has submitted a patent application (US Serial No. 09/496,824) concerning client puzzles, a technique initially described in Juels and Brainard, "Client Puzzles: A Cryptographic Countermeasure against Connection Depletion Attacks", ISOC NDSS, 1999. As of 2001, discussions within the IPsec WG had cited this technique and had considered incorporation of methods with similar properties. Related concepts were referenced in 2001 in draft-ietf-ipsec-properties-00.txt (relative to which an IPR disclosure was submitted on 3 August 2001), and more recently in draft-jennings-sip-hashcash-00.txt. If use of client puzzles is incorporated into a future Internet standard, and if the currently active application leads to an issued patent, RSA Security Inc. is willing to grant licenses to such patent under reasonable and non-discriminatory terms for purposes of implementing that Internet standard. Correspondence concerning licensing for this technology should be addressed to: RSA Security Inc., 174 Middlesex Turnpike, Bedford, MA 01730, USA, Attn: General Counsel.