I would like to write a (mobile) client and server application with a lot of similarities to PGP on the lowest application layer. Users should be able to encrypt data for multiple recipients. Moreover I need key management functionality for creating keys and exchange the public keys of the users with the application server. I would like to use one library for ios, android and the server side part (might be windows or linux). Client and server part will have the same C++ source code core, which will offer the basic crypto functionality. The C++ code will be called by JNI or other suitable interfaces. I already found the following libraries:

  1. GnuPG - Usefull, but not exactly easy to use. Therefore I searched and found:
  2. GPGME - a nice API. I started with that, until I found out that LGPL/GPL is incompatible with Apple's App Store ToS.
  3. OpenPGP-SDK - The homepage of the project seems no longer to be available. Did the move the page? Is this library still maintained? Moreover I read that it only can encrypt files with not more than ~8000 bit length. Is this true?
  4. Netpgp - Can this be used on different operating systems? Means will the library check the current operating system or will I have to use ports of Netpgp for the different platforms?
  5. UNnetpgp - I think this is sadly only suitable for iOS

Did I miss a library? Which is the easiest to use if I want to address a wide range of platforms? Maybe there is no OpenPGP library which can fulfill my requirements at all...

My first idea was to go with OpenSSL. Because I already use it for TLS encryption. But in one of my last questions I learned I should use an implementation of OpenPGP. Because I currently received the feedback to go a similar way like the one with OpenSSL - I'm now confused.

1 Answer 1


There exists our SecureBlackbox which implements complete OpenPGP functionality and is available for all major platforms. It's not free, though.

  • Such a coincidence. Just a few minutes ago I read about your product. I will take it into account. But because this is a student project our financial budget is very limited if not even non-existent. Thanks anyway. Commented Jan 6, 2016 at 11:49
  • @little_planet we have discounted and even free licenses being offered. Commented Jan 6, 2016 at 12:01
  • @ Eugene Mayevski 'EldoS Corp: as you seem to be very experienced in the openPGP area, I may ask you an beginner question. Is it possible to encrypt text (no file, it will be stored in a database) with your library? And, while I'm extracting your HTML documentation, which language is your library written in? Commented Jan 6, 2016 at 12:08
  • @little_planet yes, you can process any in-memory data. The main language is pascal, which is compiled to different targets. Commented Jan 6, 2016 at 12:15
  • 1
    I have used this product and recommend it.
    – Warren P
    Commented Sep 2, 2016 at 22:28

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