Title: CoreStreet, Ltd. Statement about IPR claimed in IETF's draft Simple Certificate Validation Protocol - ietf-pkix-scvp-18 ("SCVP"). Date: June 16, 2005 From: David Engberg, Chief Technology Officer This letter describes CoreStreet's position with respect to the current IETF IPR Policy, and provides a disclosure concerning CoreStreet patents that relate to the subject matter of the current SCVP draft (http://www.ietf.org/internet-drafts/draft-ietf-pkix-scvp-18.txt). This disclosure supersedes the prior CoreStreet disclosure dated March 23, 2005. CoreStreet understands the IPR Policy to require disclosures of intellectual property rights that are necessarily infringed by implementation of a standard with respect to which a person is contributing; in our case, the SCVP. CoreStreet believes an implementation of the SCVP standard (as currently drafted) need not necessarily infringe our patents and, for this and other reasons, believes no disclosure of our patents has been or is required. However, in order to address the concerns raised by the IETF PKIX Working Group, CoreStreet wishes to advise the IETF that it owns the following issued patents that may relate to the subject matter of the SCVP draft (ietf-pkix-scvp-18): U.S. Patent No. 5,717,758: Witness-Based Certificate Revocation System; U.S. Patent No. 5,717,757: Certificate Issue Lists; and U.S. Patent No. 5,666,416: Certificate Revocation System (collectively, the "Patents"). If the SCVP draft (ietf-pkix-scvp-18) is adopted as a standard by the IETF, and any claim in any of the Patents is necessary for implementing such standard, CoreStreet will negotiate royalty-bearing licenses of the Patents on reasonable and nondiscriminatory terms and conditions for at least any part or function of a product or service that is technically necessary for compliance with such standard, including a royalty-bearing license for any claim(s) of the Patents that would otherwise be infringed by an SCVP server to determine certificate revocation for Delegated Path Validation (DPV), provided that the royalty-bearing license is restricted to such use. In addition, CoreStreet will grant a royalty-free license for any claim(s) of the Patents that would otherwise be infringed by any product that implements an SCVP client, provided that the royalty-free license is restricted to such use. CoreStreet's obligation to grant any such license(s) is conditioned upon the prospective licensee paying reasonable royalties for the royalty-bearing license(s) and, in any case, granting a reciprocal license to CoreStreet (and its successors) of its applicable patent rights. Except as provided above, CoreStreet reserves its rights in its intellectual property. For information contact: David Engberg, Chief Technology Officer CoreStreet, Ltd. Email: dengberg@corestreet.com