OpenSSL’s new alpha build speeds up post-quantum crypto

The OpenSSL project released the first alpha of OpenSSL 4.1.0, giving developers an early look at a version built for encrypted communication over unreliable connections and faster post-quantum cryptography. This marks the opening test build for a version still months from general availability.

The headline addition is support for DTLS 1.3, the latest revision of the Datagram Transport Layer Security protocol defined in RFC 9147. DTLS secures traffic sent over UDP rather than TCP, the kind of connection used by video calls, VPNs, and IoT devices where packets can arrive late or out of order. Version 1.3 brings that traffic up to the same security baseline as TLS 1.3, closing a gap where DTLS deployments had lagged behind their TCP counterparts on features like forward secrecy and reduced handshake overhead.

OpenSSL 4.1.0 alpha1 also speeds up OpenSSL’s post-quantum algorithms, the ones designed to resist attacks from future quantum computers. It adds optimized ML-DSA and ML-KEM operations for the ppc64le architecture, ML-DSA optimizations for s390x and x86_64, and AVX-512 instructions to accelerate the SHAKE hashing that ML-DSA depends on. A separate AVX-512 and VAES optimization speeds up AES-CBC decryption on x86_64 chips. None of this changes what the algorithms do. It changes how much it costs to run them, which matters as organizations start migrating production systems to post-quantum key exchange and signatures ahead of any quantum threat materializing.