A look at the latest post-quantum signature standardization candidates

This post analyzes fourteen post-quantum signature candidates advanced to the second round of NIST's "signatures on ramp" competition. It details the cryptographic handshake process in TLS, including the roles of leaf, intermediate, and root certificates, as well as Signed Certificate Timestamps (SCTs). The post categorizes algorithms by family (Lattices, Codebased, MPC in the head, VOLE in the head, Isogeny, Multivariate) and compares their public key size, signature size, signing time, and verification time against classical and existing post-quantum schemes. It highlights the significant increase in data size required by post-quantum signatures compared to classical elliptic curves and discusses the trade-offs between signing and verification speed, as well as public key and signature size, for different TLS use cases. Specific attention is given to ML-DSA, SLH-DSA, and Falcon, noting their characteristics and potential challenges for secure implementation.