Lecture 6. SPHINCS+ (Hash-Based Signatures)

Video lectures for Alfred Menezes's introductory course on hash-based signatures including Leighton-Micali (LMS), eXtended Merkle (XMSS), and SPHINCS+. These quantum-safe signature schemes have been standardized by the Internet Engineering Task Force (IETF) and the National Institute of Standards and Technology (NIST). Topics covered: Stateful signature schemes, SPHINCS+, FIPS 205, few-times signature schemes, HORS, virtual hypertrees. Lecture playlist: https://www.youtube.com/playlist?list=PLA1qgQLL41STcDn6GCAE36RzId-Xq4JU8 Course web page: https://cryptography101.ca/crypto101-deployments/ The slides are available on the course web page. "Post-quantum cryptography" chapter from "Textbook of Applied Cryptography": https://drive.google.com/file/d/1D55HDa7imlBQXXW_CjbQftMuHZVoqNDa/view Other cryptography courses: https://cryptography101.ca Slides 00:00 Introduction 00:29 Slide 65: Stateful signature schemes 00:59 Slide 66: SPHINCS+: A stateless signature scheme 02:04 Slide 67: Few-times signature schemes 02:39 Slide 68: HORS 03:29 Slide 69: HORS: Key generation 03:55 Slide 70: HORS: Key generation 05:13 Slide 71: HORS: Key verification 05:58 Slide 72: HORS: Security analysis (1) 07:32 Slide 73: HORS: Security analysis (2) 09:12 Slide 74: Merkle tree 10:24 Slide 75: Merkle tree + Few-times signatures 11:36 Slide 76: Virtual hypertrees (1) 12:32 Slide 77: Virtual hypertrees (2) 13:48 Slide 78: Signature generation 15:03 Slide 79: Signature verification