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. embedded system security; system security;

Cryptographic Protocols.- Adaptive-ID Secure Hierarchical ID-Based Authenticated Key Exchange under Standard Assumptions without Random Oracles.- Analysis of Client-side Security for Long-term Time-stamping Services.- Towards Efficient and Strong Backward Private Searchable Encryption with Secure Enclaves.- Secure and Fair Protocols.- CECMLP: New Cipher-Based Evaluating Collaborative Multi-Layer Perceptron Scheme in Federated Learning.- Blind Polynomial Evaluation and Data Trading.- Coin-Based Multi-Party Fair Exchange.- Cryptocurrency and Smart Contracts.- P2DEX: Privacy-Preserving Decentralized Cryptocurrency Exchange.- WOTS+ up my Sleeve! A Hidden Secure Fallback for Cryptocurrency Wallets.- Terrorist Attacks for Fake Exposure Notifications in Contact Tracing Systems.- Digital Signatures.- Unlinkable and Invisible -Sanitizable Signatures.- Partially Structure-Preserving Signatures: Lower Bounds, Constructions and More.- An Efficient Certificate-Based Signature Scheme in the Standard Model.- Embedded System Security.- SnakeGX: a sneaky attack against SGX Enclaves.- Telepathic Headache: Mitigating Cache Side-Channel Attacks on Convolutional Neural Networks.- Efficient FPGA Design of Exception-Free Generic Elliptic Curve Cryptosystems.- Lattice Cryptography.- Access Control Encryption from Group Encryption.- Password Protected Secret Sharing from Lattices.- Efficient Homomorphic Conversion Between (Ring) LWE Ciphertexts.