Batched Threshold Encryption++

Rust implementation of the improved batched-threshold encryption scheme introduced in ePrint:2024/1516. For virtually all applications, this implementation should be preferred over the original scheme as it does not suffer from a per epoch setup and has a much simpler initial setup. See the paper for a detailed comparison.

Use cargo bench to benchmark encrypt, partial_decrypt and decrypt_all.

Use cargo run --example endtoend to check correctness of the implementation.

WARNING: This is an academic proof-of-concept prototype, and in particular has not received careful code review. This implementation is NOT ready for production use.

Dependencies

• arkworks project for finite field and elliptic curve arithmetic.
• merlin library for implementing the Fiat-Shamir transform.

Overview

• src/dealer: Contains an implementation of the setup methods executed by a trusted dealer for the batched threshold encryption scheme.
• src/encryption: Contains an implementation of the encrypt method for the batched threshold encryption scheme.
• src/decryption: Contains an implementation of:
  • partial_decrypt - computes the message sent by each member of the committee.
  • decrypt_all - gathers partial decryptions and recovers all messages from the batch of ciphertexts. This uses FK20 to compute all KZG opening proofs in quasi-linear time.

License

This library is released under the MIT License.