Brownie Cashlib is a cryptographic library developed at Brown University by Brownie Points Research Group. It contains many state-of-the-art cryptographic primitives including discrete-logarithm-based zero-knowledge proofs of knowledge, electronic cash, and verifiable encryption, as well as protocols including optimistic buy and barter protocols for performing fair exchange.

Cashlib and ZKPDL (the cryptographic language designed for ease-of-use) are very efficient and flexible components, enabling further additions to the library. All contributions will be appreciated.

One of the senior projects done by M. Ender Yücel at Koç University consists of adding authenticated rank-based skip lists to Brownie cashlib. Authenticated skip lists were first developed by Goodrich and Tamassia, and later improved by Papamanthou. One main use of authenticated rank-based skip lists is in secure cloud storage systems.

Pseudocodes for algorithms implemented in Cashlib provide a great resource for both users and fellow cryptographic library implementers.

The skip list code will soon be available at the Brownie Cashlib github repository.

Related Publications and Presentations:

  1. C. Chris Erway, Theodora Hinkle, Alptekin Küpçü, Anna Lysyanskaya, Sarah Meiklejohn, “ZKPDL: A Language-Based System for Efficient Zero-Knowledge Proofs and Electronic Cash“, USENIX Security 2010.
  2. M. Ender Yücel, “Trust Me: Authenticated Data Structures“, Koç University Senior Project poster, 2011.