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​​🗓️ About the event

​Threshold Key Generation and Decryption for fhEVM Chains

​By Tore Frederiksen

An important part of building confidential smart contracts that meet the demands of modern applications, is the ability to easily mix data from multiple users and to develop contracts in a composable manner. One way to facilitate this is through fully homomorphic encryption under a single public key, with smart contracts determining who can decrypt which ciphertext. In order to securely manage keys and decryptions for the network, we introduce  advanced MPC protocols to achieve a fully functioning decentralized KMS system through threshold secret sharing. The KMS allows us to generate TFHE keys and execute decryption in a threshold manner such that the private decryption key never exists at any single party in clear text at any point; thus keeping with the distributed security ethos of the blockchain.

​In this talk, we detail our threshold KMS through its core MPC protocols, the implementation architecture, and its application to confidential smart contracts. We discuss performance and some of the challenges we faced when developing MPC protocols for blockchains.

​🟨 About Zama

​Zama is an open source cryptography company building state-of-the-art FHE solutions for blockchain and AI.

​Check out Zama's events during EthCC at: zama.ai/the-cofhe-shop

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