SHA-1

1 General

• digest size: 160 bits
• max. message length: < 2⁶⁴ bits
• compression function: 512-bit message block, 160-bit chaining variable
• Specification: FIPS 180-2 Secure Hash Standard

2 Cryptanalysis

2.1 Best Known Results

The best collision attack on full SHA-1 was published by Wang et al. It has complexity of 2⁶⁹ hash evaluations. The best collision example, a 70-step collision for SHA-1, was publshed by DeCanniere, Mendel and Rechberger.

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2.3 Preimage Attacks

• We are not aware of any articles w.r.t. preimage attacks on SHA-1.

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3 eHash Recommendation (optional) or eHash Opinion

Something like: SHA-1 is considered to be broken. Please do not incorporate SHA-1 in new application any longer. Try to migrate to another hash function.