Cryptimeleon - prototyping for advanced privacy-preserving constructions

Cryptimeleon (pronounced /krɪptimiːliən/, “cryp-tee-meleon”) is an open-source Java library primarily aimed at cryptography researchers.

You want to prototype and benchmark your new kind of anonymous credentials, group signatures, attribute-based encryption, or other construction in the bilinear group setting?

Try Cryptimeleon!

✅ What Cryptimeleon offers

Cryptimeleon supports the following features (plus others):

  • Write equations in our simple algebraic (bilinear groups) framework.
    • Easily readable, e.g., g.pow(m).op(h.pow(r)).
    • Easy parallelism and precomputation. Transparent multiexponentiation.
    • Same abstraction as in conference papers. We’re taking care of point-on-curve and subgroup checks.
  • Benchmark your construction (in milliseconds or count group operations)
    • Put convincing numbers into your paper.
    • Android support - benchmark modern crypto on a phone.
  • Implement Schnorr-style zero-knowledge proofs.
    • Specify them using Camenisch-Stadler notation in subzero to generate code.
    • Supports AND/OR composition, range proofs, pairing support, Fiat-Shamir, etc.
  • Use the basics you may expect: hash into groups or \(\mathbb{Z}_p\), use pseudorandom function and random oracles with arbitrary input/output length, …
  • No copyright issues: Open-source under Apache 2.0 license.

❌ What Cryptimeleon does not offer

  • Do not use Cryptimeleon for production code. It is a research tool only and may not offer the security level required in real applications.
  • Do not use Cryptimeleon if you want to implement absurd levels of performance optimization.
    • We focus more on easy-to-read APIs than performance.
    • That said, benchmarks with Cryptimeleon are definitely competitive and we do automatically optimize some things in the background.

Getting started

  • 🙋 To read more, consider our paper [to be published].
  • 🧑‍💻 To see example code, read the 5 minute tutorial or generate a Sigma protocol with subzero.
  • 👷 To build your own application with Cryptimeleon, import our projects via Maven or gradle. Check out our “how do I …” page if you’re stuck.
  • 🧙 For everything else, consult this documentation page, follow our Twitter, find the code on GitHub, or contact us.


We have a paper on Cryptimeleon and its features published on eprint. The paper also highlights the benefits that Cryptimeleon provides for privacy-preserving cryptography researchers .

How to cite

  author    = {Jan Bobolz and
               Fabian Eidens and
               Raphael Heitjohann and
               Jeremy Fell},
  title     = {Cryptimeleon: A Library for Fast Prototyping of Privacy-Preserving Cryptographic Schemes},
  journal   = { {IACR} Cryptol. ePrint Arch.},
  volume    = {2021},
  pages     = {961},
  year      = {2021},
  url       = {},

🏫 Cryptimeleon has been developed at Paderborn University (Germany) in the Codes and Cryptography group.