Threshold Cryptography | Kuneco April 2021

1. Introduction

The video introduces the topic of threshold cryptography and provides background information about the speakers, Kobe and Nicolas. It emphasizes their practical approach to building trustless coordination systems and their expertise in cryptography.

2. The Importance of Randomness

This section explains the significance of randomness in various domains, including lotteries, choices, selections, and cryptographic protocols. It highlights the necessity of randomness for secure protocols, such as zero-knowledge proofs, clearances, and divinations.

3. Application of Randomness in Blockchain

The tutorial discusses the application of randomness in blockchain systems, particularly in leader elections and block creation. It presents the challenges faced by existing solutions like proof-of-work and proof-of-stake, highlighting the issues of centralization and vulnerabilities. It also introduces the concept of a distributed randomness beacon service, such as D-Rand, as a promising solution for providing randomness in blockchain.

4. Overview of Threshold Cryptography

This section provides an overview of threshold cryptography and its significance in generating secure signatures. It explains the setup phase, where participants share secret shares, and the lagrangian interpolation, which combines the shares to create partial signatures. The tutorial also briefly mentions the verification equation and the benefits of threshold cryptography, such as unbiased randomness.

5. How Threshold Cryptography Works

This section explains the workings of threshold cryptography in more detail. It discusses the time-consistency of the protocol, allowing groups to change in size and maintain constant public keys. The tutorial describes the process of sharing secret shares among participants and the use of lagrangian interpolation to combine the partial signatures. It also mentions the availability and security measures taken in the implementation of threshold cryptography.

6. Use Cases of Threshold Cryptography

This section highlights the practical applications of threshold cryptography. It mentions the League of Entropy, a production-grade implementation of threshold cryptography used for generating random numbers. The tutorial also mentions password hardening and account recovery as additional use cases where threshold cryptography can enhance security.

7. Conclusion

The video concludes by summarizing the key points discussed in the transcript. It encourages further exploration of the topic and provides links to relevant resources, including the recorded talks and codebase.