The four-volume set, LNCS 16551-16554, constitutes the refereed proceedings of the 29th IACR International Conference on Practice and Theory of Public-Key Cryptography, held in West Palm Beach, FL, USA, during May 25–28, 2026.The 65 papers included in these proceedings were carefully reviewed and selected from 259 submissions. They are organized in topical sections as follows:Part I: Lattice Foundations and KEM; Signature Schemes; CryptanalysisPart II: Foundations and Security Definitions; MPC and Friends; CommitmentsPart III: Isogenies and Curves; Proof Systems and Functional Encryption; Credentials and Advanced SignaturesPart IV: Advanced Encryption and Privacy; Homomorphic and Searchable Encryption; Protocols and Real-World Security
