The four-volume set, LNCS 12825, LNCS 12826, LNCS 12827, and LNCS 12828, constitutes the refereed proceedings of the 41st Annual International Cryptology Conference, CRYPTO 2021. Crypto has traditionally been held at UCSB every year, but due to the COVID-19 pandemic it was an online event in 2021.The 103 full papers presented in the proceedings were carefully reviewed and selected from a total of 426 submissions. The papers are organized in the following topical sections: Part I: Award Papers; Signatures; Quantum Cryptography; Succinct Arguments. Part II: Multi-Party Computation; Lattice Cryptography; and Lattice Cryptanalysis. Part III: Models; Applied Cryptography and Side Channels; Cryptanalysis; Codes and Extractors; Secret Sharing. Part IV: Zero Knowledge; Encryption++; Foundations; Low-Complexity Cryptography; Protocols.

The four-volume set, LNCS 12825, LNCS 12826, LNCS 12827, and LNCS 12828, constitutes the refereed proceedings of the 41st Annual International Cryptology Conference, CRYPTO 2021. Crypto has traditionally been held at UCSB every year, but due to the COVID-19 pandemic it was an online event in 2021.The 103 full papers presented in the proceedings were carefully reviewed and selected from a total of 426 submissions. The papers are organized in the following topical sections: Part I: Award Papers; Signatures; Quantum Cryptography; Succinct Arguments. Part II: Multi-Party Computation; Lattice Cryptography; and Lattice Cryptanalysis. Part III: Models; Applied Cryptography and Side Channels; Cryptanalysis; Codes and Extractors; Secret Sharing. Part IV: Zero Knowledge; Encryption++; Foundations; Low-Complexity Cryptography; Protocols.

The four-volume set, LNCS 12825, LNCS 12826, LNCS 12827, and LNCS 12828, constitutes the refereed proceedings of the 41st Annual International Cryptology Conference, CRYPTO 2021. Crypto has traditionally been held at UCSB every year, but due to the COVID-19 pandemic it was an online event in 2021.The 103 full papers presented in the proceedings were carefully reviewed and selected from a total of 426 submissions. The papers are organized in the following topical sections: Part I: Award Papers; Signatures; Quantum Cryptography; Succinct Arguments. Part II: Multi-Party Computation; Lattice Cryptography; and Lattice Cryptanalysis. Part III: Models; Applied Cryptography and Side Channels; Cryptanalysis; Codes and Extractors; Secret Sharing. Part IV: Zero Knowledge; Encryption++; Foundations; Low-Complexity Cryptography; Protocols.

The four-volume set, LNCS 12825, LNCS 12826, LNCS 12827, and LNCS 12828, constitutes the refereed proceedings of the 41st Annual International Cryptology Conference, CRYPTO 2021. Crypto has traditionally been held at UCSB every year, but due to the COVID-19 pandemic it was an online event in 2021.The 103 full papers presented in the proceedings were carefully reviewed and selected from a total of 426 submissions. The papers are organized in the following topical sections: Part I: Award Papers; Signatures; Quantum Cryptography; Succinct Arguments. Part II: Multi-Party Computation; Lattice Cryptography; and Lattice Cryptanalysis. Part III: Models; Applied Cryptography and Side Channels; Cryptanalysis; Codes and Extractors; Secret Sharing. Part IV: Zero Knowledge; Encryption++; Foundations; Low-Complexity Cryptography; Protocols.

Lattice-based cryptography is the use of conjectured hard problems on point lattices in Rn as the foundation for secure cryptographic systems. Attractive features of lattice cryptography include apparent resistance to quantum attacks (in contrast with most number-theoretic cryptography), high asymptotic efficiency and parallelism, security under worst-case intractability assumptions, and solutions to long-standing open problems in cryptography. This monograph surveys most of the major developments in lattice cryptography over the past ten years. The main focus is on the foundational short integer solution (SIS) and learning with errors (LWE) problems (and their more efficient ring-based variants), their provable hardness assuming the worst-case intractability of standard lattice problems, and their many cryptographic applications.