Off The Record (OTR) messaging cryptography protocol library in C# for Windows 8 Runtime. This was done during the Facebook/Windows Hackathon to create SecureChat for Facebook Windows 8 App.
- Confidentiality so that the messages are encrypted.
- Authentication that verifies who the initiator and receiver are.
- Perfect Forward Secrecy so that each instant message sent is encrypted using a different encryption key.
- Deniability, so that the MAC keys that already have been used will not be used again.
This was developed by Code Project Don Fizachi originally for .NET. We converted it to run on the Windows 8 Runtime. These areas has changed:
- Windows 8 Runtime APIs do not support System.Security.Cryptography. The cryptography methods had to be rewritten using the Windows.Security.Cryptography methods.
- Exception handling had to change to support Windows Runtime
- Logging had to change
- Random Byte Generator had to change using different approach