1. Theoretical and Practical Collision Milestones
• 2005: Cryptanalysts demonstrated theoretical collision attacks requiring 2^63 operations (far below the theoretical 2^80 design threshold).
• 2017: The SHAttered attack achieved the first real-world practical SHA-1 collision, creating two distinct PDF documents with identical SHA-1 hashes.
• 2020: Chosen-prefix collisions for SHA-1 became practical for under $45,000 in cloud compute costs.
2. Regulatory Ban
NIST officially mandates that SHA-1 must be fully deprecated across all government and security contexts by December 31, 2030.