Insynd is a secure and privacy-friendly one-way messaging system developed in the EU FP-7 project A4Cloud, enabling senders to send messages to potentially offline recipients. Insynd is asynchronous, tamper-evident, encrypts messages using state-of-the-art algorithms, prevents some information leaks, publicly verifiable, safe to outsource, enables both sender and recipient to prove several properties of sent messages, and supports distributed settings.

Insynd’s primary role in A4Cloud is to facilitate the communication of data from data controllers to data subjects. Insynd can be seen as a secure and privacy friendly replacement of email where the sender is fixed (the data controller) and recipients (data subjects) have to register at the sender (similar to providing their email address). In A4Cloud, other tools will provide notifications generated at the data controller that should be parsed by other tools used by a data subject. Insynd plays the role of a privacy friendly transport of these notifications.

Papers

• Insynd: Privacy-Preserving Secure One-Way Messaging Using Balloons
  Tobias Pulls and Roel Peeters
  Cryptology ePrint Archive, Report 2015/150, 2015
• Balloon: A Forward-Secure Append-Only Persistent Authenticated Data Structure
  Tobias Pulls and Roel Peeters
  Cryptology ePrint Archive, Report 2015/007, 2015
• Distributed Privacy-Preserving Transparency Logging
  Tobias Pulls, Roel Peeters, Karel Wouters
  In Proc. of: Workshop on Privacy in the Electronic Society, 2013, ACM
• Enhancing Transparency with Distributed Privacy-Preserving Logging
  Roel Peeters, Tobias Pulls, Karel Wouters
  In Highlights of the Information Security Solutions Europe 2013 Conference

Code

Latest release 2015.03. WARNING: this is a proof-of-concept implementation under active development and should not be used by anyone for any serious use. At the time of writing this warning (2015-01-12), we are aware of a number of shortcomings in the latest release. Some will be sorted out in future releases, others are out of scope of A4Cloud and will never be addressed.

git clone http://www.cs.kau.se/pulls/insynd.git/

License

Copyright 2015 Karlstad University

Licensed under the Apache License, Version 2.0 (the “License”); you may not use this file except in compliance with the License. You may obtain a copy of the License at

http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an “AS IS” BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.

Reproducing Benchmarks

To reproduce the benchmarks from th Insynd paper: clone the repositry, setup Go, set GOPATH to point to the root of the repository, and then run

make paperbenchmark

The graphs were generated using matplotlib.

Contact

Tobias Pulls <tobias.pulls@kau.se>