Signature Schemes -- Group Signature without Random Oracles from Randomizable Signatures -- Constant-size Lattice-Based Group Signature with Forward Security in the Standard Model -- A Lattice-based Provably Secure Multisignature Scheme in Quantum Random Oracle Model -- Achieving Pairing-Free Aggregate Signatures using Pre-Communication between Signers -- Short Lattice Signatures in the Standard Model with Efficient Tag Generation -- One-Time Delegation of Unlinkable Signing Rights and Its Application -- Watermarkable Signature with Computational Function Preserving -- Privacy-Preserving Authentication for Tree-Structured Data with Designated Verification in Outsourced Environments -- Encryption Schemes and NIZKs -- Semi-Adaptively Secure Offine Witness Encryption from Puncturable Witness PRF.-Improved Indistinguishability for Searchable Symmetric Encryption -- Receiver Selective Opening CCA Secure Public Key Encryption from Various Assumptions -- A Practical NIZK Argument for Confidential Transactions over Account-model Blockchain -- Secure Machine Learning and Multiparty Computation -- Secure Cumulative Reward Maximization in Linear Stochastic Bandits -- Secure Transfer Learning for Machine Fault Diagnosis under Different Operating Conditions -- Private Decision Tree Evaluation with Constant Rounds via (Only) SS-3PC over Ring -- Dispelling Myths on Superposition Attacks: Formal Security Model and Attack Analyses -- Secret Sharing Schemes -- Fair and Sound Secret Sharing from Homomorphic Time-Lock Puzzles -- Optimal Threshold Changeable Secret Sharing with New Threshold Change Range -- Security Analyses -- Key Recovery under Plaintext Checking Attack on LAC -- Security of Two NIST Candidates in the Presence of Randomness Reuse.

This book constitutes the refereed proceedings of the 14th International Conference on Provable Security, ProvSec 2020, held in Singapore, in November 2020. The 20 full papers presented were carefully reviewed and selected from 59 submissions. The papers focus on provable security as an essential tool for analyzing security of modern cryptographic primitives. They are divided in the following topical sections: signature schemes, encryption schemes and NIZKS, secure machine learning and multiparty computation, secret sharing schemes, and security analyses. * The conference was held virtually due to the COVID-19 pandemic.