A new Request for Comments is now available in online RFC libraries. RFC 5752 Title: Multiple Signatures in Cryptographic Message Syntax (CMS) Author: S. Turner, J. Schaad Status: Standards Track Date: January 2010 Mailbox: turners@ieca.com, jimsch@exmsft.com Pages: 17 Characters: 34502 Updates/Obsoletes/SeeAlso: None I-D Tag: draft-ietf-smime-multisig-05.txt URL: http://www.rfc-editor.org/rfc/rfc5752.txt Cryptographic Message Syntax (CMS) SignedData includes the SignerInfo structure to convey per-signer information. SignedData supports multiple signers and multiple signature algorithms per signer with multiple SignerInfo structures. If a signer attaches more than one SignerInfo, there are concerns that an attacker could perform a downgrade attack by removing the SignerInfo(s) with the 'strong' algorithm(s). This document defines the multiple-signatures attribute, its generation rules, and its processing rules to allow signers to convey multiple SignerInfo objects while protecting against downgrade attacks. Additionally, this attribute may assist during periods of algorithm migration. [STANDARDS TRACK] This document is a product of the S/MIME Mail Security Working Group of the IETF. This is now a Proposed Standard Protocol. STANDARDS TRACK: This document specifies an Internet standards track protocol for the Internet community,and requests discussion and suggestions for improvements. Please refer to the current edition of the Internet Official Protocol Standards (STD 1) for the standardization state and status of this protocol. Distribution of this memo is unlimited. This announcement is sent to the IETF-Announce and rfc-dist lists. To subscribe or unsubscribe, see http://www.ietf.org/mailman/listinfo/ietf-announce http://mailman.rfc-editor.org/mailman/listinfo/rfc-dist For searching the RFC series, see http://www.rfc-editor.org/rfcsearch.html. For downloading RFCs, see http://www.rfc-editor.org/rfc.html. Requests for special distribution should be addressed to either the author of the RFC in question, or to rfc-editor@rfc-editor.org. Unless specifically noted otherwise on the RFC itself, all RFCs are for unlimited distribution. The RFC Editor Team Association Management Solutions, LLC _______________________________________________ IETF-Announce mailing list IETF-Announce@ietf.org https://www.ietf.org/mailman/listinfo/ietf-announce