This library contains a small implementation of witness encryption for succinct functional commitments for Libert et al.’s FC.
❗ This library has not been audited and should not be used in production
Witness encryption allows you to encrypt a value to whoever has knowledge of a witness. More concretely, in this work, the encryption statement consists of a commitment cm, a function G and a value y; the decryption witness consists of a (non succinct) NIZK proof about the fact that cm opens to v such that y=G(v).
The above is made possible through two main building blocks:
- Smooth Projective Hash Functions
- Functional Commitments
To see how it can be used, run cargo test encryption_decryption.
The SPHF tests use examples from Fabrice Benhamouda's thesis: Diverse modules and zero-knowledge.
A big thank you to the authors of Witness Encryption for Succinct Functional Commitments and Applications and its sources. Moreover, this existing SPHF repo was a great help.