Published: 2026-08-20Standard:
Cryptographic Reference Guide
Is SHA-1 Secure? The SHAttered Attack and Deprecation Timeline
Why NIST and web browsers formally deprecated SHA-1, how chosen-prefix attacks work, and current compliance mandates.
Frequently Asked Questions.
Frequently Asked Questions
Clear answers to common cryptographic and implementation questions.
Can an attacker forge a SHA-1 certificate?
Yes. With practical chosen-prefix collisions, an attacker can create two distinct certificates with identical SHA-1 signatures.