Dear all,

with the acceptance of the paper “Keeping Authorities ‘Honest or Bust’ with Decentralized Witness Cosigning” http://arxiv.org/abs/1503.08768 at IEEE S&P 2016 http://www.ieee-security.org/TC/SP2016/, we updated our code to make it even more easy to integrate it with your projects.

For details on how to use the CoSi-application, go to https://github.com/dedis/cosi/blob/master/README.md .

The code is now based on our latest cothority-framework and can be called from your program to generate a collective signature of a file. The same code also verifies the signature or can be used as a server if you want to run your own cothority-group.

There are two proposals to include the collective signing and verification in open-source-libraries:

• Go crypto library: https://github.com/bford/golang-x-crypto
• C libsodium: https://github.com/bford/libsodium Both forks can be used to verify the signatures created by our latest CoSi-release.

If you have questions or remarks, feel free to contact us here or open issues on https://github.com/dedis/cosi .

Yours, the DeDiS-team