1. 1 Authentication Algorithm Document Discussions CCSDS Security Working Group Fall 2007 Meeting 3-5 October 2007 ESA/ESOC, Darmstadt Germany (Hotel am Bruchsee, Heppenheim)

2. 2 Background Authentication algorithms proposed for CCSDS “standardization” – Originally to be a Blue Book – Compromise resulting in document being a Magenta Book (best practice) Proposes the use of HMAC-SHA-256 and Digital Signature Algorithm (DSA) – HMAC-SHA-1 for non-public key environments – DSA for public key environments – HMAC may be used with other hash algorithms » SHA-256 » SHA-512 » RIPEMD » Tiger » etc

3. 3 Document Status Discussed at Leatherhead meeting: – Same ‘class’ of changes made to this document as to the encryption algorithm document » Reference added for source of definitions – FIPS 198-1 (like CCSDS) does not recommend HMAC truncation and reference should be updated when 198- 1 is no longer a draft – Are we ready to send this out for Agency Review?