Botan 3.5.0

LMS/HSS Stateful Hash-based signatures

Botan 3.4.0

Notable additions:

• X448 and Ed448 (classical elliptic curve schemes)

Botan 3.3.0

Notable additions:

• FrodoKEM (NIST Round 3 "alternate candidate", proposed ISO standard)
• TLS 1.3
  • use "raw public keys" for authentication (RFC 7250)
  • TLS policy BSI_TR_02102_2 enables TLS 1.3 by default
• Mitigations for Side Channels in Kyber

Botan 3.2.0

Notable additions:

• Support for TLS hybrid key exchange compatible with draft-ietf-tls-hybrid-design
• TLS 1.3 with pre-shared keys
• Addition of KMAC

Botan 3.1.1

Notable additions since the last audited version of Botan (2.14.0):

• TLS 1.3
• Implementations of NIST Round 3 Post-Quantum Algorithms:
  • Kyber 3.02
  • Dilithium 3.1
  • SPHINCS+
• Requires C++20, therefore at least:
  • GCC 11
  • Clang 14
  • MSVC 2022

Specifically note the extensive migration guide outlining braking changes from Botan 2.x to 3.x.