Lunar: a Toolbox for More Efficient Universal and Updatable zkSNARKs and Commit-and-Prove Extensions -- Gentry-Wichs Is Tight: A Falsifiable Non-Adaptively Sound SNARG -- Proofs for Inner Pairing Products and Applications -- Snarky Ceremonies -- Efficient NIZKs for Algebraic Sets -- Bit Security as Computational Cost for Winning Games with High Probability -- Giving an Adversary Guarantees (Or: How to Model Designated Verifier Signatures in a Composable Framework) -- How to Build a Trapdoor Function from an Encryption Scheme -- Beyond Software Watermarking: Traitor-Tracing for Pseudorandom Functions -- Batching Base Oblivious Transfers -- Algebraic Adversaries in the Universal Composability Framework -- Luby-Rackoff Backwards with More Users and More Security -- Double-Block-Length Hash Function for Minimum Memory Size -- Toward a Fully Secure Authenticated Encryption Scheme From a Pseudorandom Permutation -- Tight Security for Key-Alternating Ciphers with Correlated Sub-Keys -- FAST: Secure and HighPerformance Format-Preserving Encryption and Tokenization -- Fine-tuning the ISO/IEC Standard LightMAC -- Categorization of Faulty Nonce Misuse Resistant Message Authentication -- Balanced Non-Adjacent Forms -- Efficient Boolean Search over Encrypted Data with Reduced Leakage -- Revisiting Homomorphic Encryption Schemes for Finite Fields -- Transciphering Framework for Approximate Homomorphic Encryption -- Improved Programmable Bootstrapping with Larger Precision and Efficient Arithmetic Circuits for TFHE.

The four-volume proceedings LNCS 13090, 13091, 13092, and 13093 constitutes the proceedings of the 27th International Conference on the Theory and Application of Cryptology and Information Security, ASIACRYPT 2021, which was held during December 6-10, 2021. The conference was planned to take place in Singapore, but changed to an online format due to the COVID-19 pandemic. The total of 95 full papers presented in these proceedings was carefully reviewed and selected from 341 submissions. The papers were organized in topical sections as follows: Part I: Best paper awards; public-key cryptanalysis; symmetric key cryptanalysis; quantum security; Part II: physical attacks, leakage and countermeasures; multiparty computation; enhanced public-key encryption and time-lock puzzles; real-world protocols; Part III: NIZK and SNARKs; theory; symmetric-key constructions; homomorphic encryption and encrypted search; Part IV: Lattice cryptanalysis; post-quantum cryptography; advanced encryption and signatures; zero-knowledge proofs, threshold and multi-signatures; authenticated key exchange.