This book constitutes the proceedings of the 18th International Conference on Provable and Practical Security, ProvSec 2024, which took place in Gold Coast, QLD, Australia, during September 25-27, 2024. The 26 full papers and 8 short papers presented were thoroughly reviewed and selected from the 79 submissions.

.- Multi-Party Computation. .- SecFloatPlus: More Accurate Floating-Point Meets Secure Two-Party Computation. .- Consecutive Adaptor Signature Scheme: From Two-Party to N-Party Settings. .- Secure Five-party Computation with Private Robustness and Minimal Online Communication. .- Model Extraction Attack on MPC Hardened Vertical Federated Learning. .- Searchable Encryption. .- Verifiable Conjunctive Searchable Symmetric Encryption with Result Pattern Hiding. .- Compressed Cookies: Practical Wildcard Symmetric Searchable Encryption with Optimized Storage. .- Encryption. .- PPA-DCA: A Privacy-Preserving and Accountable Data Collection and Analysis Scheme Using Decentralized Multi-Client Functional Encryption. .- Ideal Public Key Encryption, Revisited. .- Simple Construction of PEKS from LWE-based IBE in the Standard Model. .- Signature. .- Traceable Ring Signatures: Logarithmic-Size, Without Any Setup, from Standard Assumptions. .- Tightly Secure Identity-based Signature from Cryptographic Group Actions. .- Generic Construction of Withdrawable Signature from Hash-ThenOne-Way Signature. .- Efficient Fork-Free BLS Multi-Signature Scheme with Incremental Signing. .- Threshold Ring Signatures: From DualRing to the t+1 Rings. .- Lattice-Based Non-Interactive Blind Signature Schemes in the Random Oracle Model.