This book constitutes the refereed proceedings of the 27th Australasian Conference on Information Security and Privacy, ACISP 2022, held in Wollongong, NSW, Australia, in November 2022.The 25 full papers presented were carefully revised and selected from 62 submissions.

Symmetric-Key Cryptography.- Key Structures: Improved Related-Key Boomerang Attack against the Full AES-256.- Truncated Differential Properties of the Diagonal Set of Inputs for 5-round AES.- PNB-focused Differential Cryptanalysis of ChaCha Stream Cipher.- Improved Differential Attack on Round-Reduced LEA.- Implementing Grover Oracle for Lightweight Block Ciphers under Depth Constraints.- Improved Division Property for Ciphers with Complex Linear Layers.- Fast Skinny-128 SIMD Implementations for Sequential Modes of Operation.- Public-Key Cryptanalysis.- Handle the Traces: Revisiting the Attack on ECDSA with EHNP.- Hybrid Dual and Meet-LWE Attack.- Cryptanalysis and Repair of a Gabidulin Code Based Cryptosystem from ACISP 2018.- Public-Key Cryptography.- Chosen Ciphertext Secure Keyed Two-Level Homomorphic Encryption.- Structure-preserving Linearly Homomorphic Signature with Designated Combiner for Subspace.- TIDE: A novel approach to constructing timed-release encryption.- Multi-signatures for ECDSA and its Applications in Blockchain.- Post-Quantum Cryptography.- Fiat-Shamir Signatures based on Module-NTRU.- Speeding-Up Parallel Computation of Large Smooth-Degree Isogeny using Precedence-Constrained Scheduling.- An Injectivity Analysis of Crystals-Kyber and Implications on Quantum Security.- Cryptographic Protocols.- Verifiable Decryption in the Head.- Resumable Zero-Knowledge for Circuits from Symmetric Key Primitives.- On Security of Fuzzy Commitment Scheme for Biometric Authentication.- SoK: Decentralized Randomness Beacon Protocols.- Blockchain.- CCOM: Cost-Efficient and Collusion-Resistant Oracle Mechanism for Smart Contracts.- DeChain: A Blockchain Framework Enhancing Decentralization via Sharding.- Garrison: A Novel Watchtower Scheme for Bitcoin.- Shoot Before You Escape: Dynamic Behavior Monitor of Bitcoin Users via Bi-Temporal Network Analytics.