The four-volume set LNCS 16268-16271 constitutes the refereed proceedings of the 23rd International Conference on Theory of Cryptography, TCC 2025, held in Aarhus, Denmark, during December 1 5, 2025. The total of 70 full papers presented in the proceedings was carefully reviewed and selected from 242 submissions. They were organized in topical sections as follows:
Part I: Secure Computation; Homomorphic Primitives; Proofs;
Part II: Foundations; Obfuscation and Functional Encryption; Secret Sharing;
Part III: Quantum Cryptography; Signatures and Intractability Assumptions;
Part IV: Proofs; Young Researcher Award and Outstanding Paper Awards; Differential Privacy; Times Cryptography and Verifiable Random Function; Secure Computation.
.- Quantum Cryptography I.
.- Untelegraphable Encryption and its Applications.
.- A Computational Monogamy of Entanglement Theorem with 1 Applications to Non-Interactive Quantum Key Distribution.
.- On the Limitations of Pseudorandom Unitaries.
.- Clifford Strategies in Interactive Protocols are Classically Simulatable.
.- Pseudorandom Function-like States from Common Haar Unitary.
.- Foundations of Single-Decryptor Encryption.
.- Signatures and Intractability Assumptions.
.- Security Amplification of Threshold Signatures in the Standard Model.
.- Sandwich BUFF: Achieving Non-Resignability Using Iterative Hash Functions
.- Unconditional foundations for supersingular isogeny-based cryptography.
.- The Pseudorandomness of Legendre Symbols under the Quadratic
Residuosity Assumption
.- Dimensional eROSion: Improving the ROS Attack with Decomposition in Higher Bases
.- Threshold Signatures from One-Way Functions.
.- Quantum Cryptography II.
.- How to Verify that a Small Device is Quantum, Unconditionally.
.- Quantum Interactive Oracle Proofs.
.- NISQ Security and Complexity via Simple Classical Reasoning.
.- Quantum Rewinding for IOP-Based Succinct Arguments.
