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As of January 1, 2014, NIST disallows the use of the SHA-1 digest algorithm in conjunction with digital signatures (see: NIST SP 800-57 Part 1, Revision 3, July 2012, Tables 3 and 4). This was a major driver behind the Phase 1 Recommendations of the Metadata Distribution Working Group, which gave rise to the Phase 1 Implementation Plan, a major effort to phase out SHA-1 in InCommon metadata that began on December 18, 2013 and ended on June 30, 2014.
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