OpenSSL 4.1.0 adds DTLS 1.3 support and post-quantum optimizations

OpenSSL 4.1.0 has been released as a major feature update, bringing critical protocol support and architectural improvements. The release introduces DTLS 1.3 (RFC 9147) and RFC 8701 GREASE support, alongside initial compatibility for the Elbrus2000 (e2k) architecture. Additionally, the update includes significant cryptographic optimizations for post-quantum algorithms like ML-DSA and ML-KEM on x86_64 and ppc64le platforms. Users should note that several legacy Windows targets have been dropped and certain configuration options have changed.

Technical improvements in OpenSSL 4.1.0

• Protocol Updates: Added support for DTLS 1.3 (RFC 9147), IKEV2 KDF, and RFC 8701 GREASE to improve extensibility and security.
• Post-Quantum Cryptography: Implemented optimized ML-DSA and ML-KEM NTT operations on ppc64le, as well as AVX-512-optimized SHAKE x4 and AES-CBC decryption on x86_64.
• Architecture & Platform Support: Introduced initial support for the Elbrus2000 (e2k) architecture and added MSVC 2013 build targets for better C99 compliance on Windows.
• Deprecations: Removed Windows-on-Itanium (VC-WIN64I) and Windows CE (VC-CE) targets, and replaced the abandoned WWW::Curl::Easy with Net::Curl::Easy in the tsget utility.

Why it matters

This release accelerates the adoption of post-quantum cryptography standards and modern DTLS protocols across the internet infrastructure. Developers working on high-performance networking or specialized hardware like Elbrus2000 will benefit from these architectural and cryptographic refinements.