The two-volume set LNCS 12726 + 12727 constitutes the proceedings of the 19th International Conference on Applied Cryptography and Network Security, ACNS 2021, which took place virtually during June 21-24, 2021.
The 37 full papers presented in the proceedings were carefully reviewed and selected from a total of 186 submissions. They were organized in topical sections as follows:
Part I: Cryptographic protocols; secure and fair protocols; cryptocurrency and smart contracts; digital signatures; embedded system security; lattice cryptography;
Part II: Analysis of applied systems; secure computations; cryptanalysis; system security; and cryptography and its applications.

Analysis of Applied Systems.- Breaking and Fixing Third-Party Payment Service for Mobile Apps.- DSS: Discrepancy-Aware Seed Selection Method for ICS Protocol Fuzzing.- Threat for the Secure Remote Password Protocol and a Leak in Apple's Cryptographic Library.- Secure Computations.- Privacy-Preserving Data Aggregation with Probabilistic Range Validation.- LLVM-based Circuit Compilation for Practical Secure Computation.- An Efficient Passive-to-Active Compiler for Honest-Majority MPC over Rings.- Cryptanalysis.- Experimental Review of the IKK Query Recovery Attack: Assumptions, Recovery Rate and Improvements.- Efficient Methods to Search for Best Differential Characteristics on SKINNY.- Towards Efficient LPN-Based Symmetric Encryption.- System Security.- A Differentially Private Hybrid Approach to Traffic Monitoring.- Proactive Detection of Phishing Kit Traffic.- Vestige: Identifying Binary Code Provenance for Vulnerability Detection.- SoK: Auditability and Accountability in DistributedPayment Systems.- Defending Web Servers Against Flash Crowd Attacks.- Cryptography and its Applications.- TurboIKOS: Improved Non-interactive Zero-Knowledge and Post-Quantum Signatures.- Cryptanalysis of the Binary Permuted Kernel Problem.- Security Comparisons and Performance Analyses of Post-Quantum Signature Algorithms.- Tighter Proofs for the SIGMA and TLS 1.3 Key Exchange Protocols.- Improved Structured Encryption for SQL Databases via Hybrid Indexing.