Public Report – Threshold ECDSA Cryptography Review

In March 2022, DFINITY engaged NCC Group to conduct a security and cryptography review of a threshold ECDSA implementation, which follows a novel approach described in the reference paper entitled “Design and analysis of a distributed ECDSA signing service” and available on the IACR ePrint archive at The threshold ECDSA protocol will be deployed into the architecture of the Internet Computer. The ability for canisters to perform threshold signature generation and verification will facilitate the integration of the Internet Computer with other blockchains using ECDSA signatures, including Bitcoin and Ethereum.

The project methodology primarily relied upon manual code review supported by dynamic interaction with the test cases, as well as review of the supporting reference paper. Following this review, in early May 2022, NCC Group performed a retest of the findings uncovered during the initial engagement. That follow-up engagement also included the review of a short pull request incorporating changes to the underlying encryption scheme.

The Public Report for this review may be downloaded below: