OpenSSL 4.1 adds DTLS 1.3 and broader TLS and crypto improvements

OpenSSL 4.1 is a substantial protocol and performance release: it adds DTLS 1.3, TLS GREASE support, and AVX-512 acceleration for SHAKE x4 operations used by ML-DSA and AES-CBC decryption.

DTLS 1.3 brings faster handshakes and forward secrecy for datagram-based secure connections. GREASE sends reserved, meaningless values in TLS handshakes to expose peers that mishandle unknown protocol codes. The two-comment thread welcomed the release; one reader separately criticized Firefox’s current handling of Ed25519-signed certificates, which is not a change addressed by this release.