$ python3
Python 3.6.3 (default, Oct 3 2017, 21:45:48)
[GCC 7.2.0] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> 4/3
1.3333333333333333
Python3 is basically a different language than Python 2. If I wanted to port software to a different language, I would use any number of available languages that make other kinds of improvements over Python as well. The only remaining use case for Python for me will be as a quick scripting language, and data analysis and graphing tool.
I totally agree with the idea that if software uses encryption, it should be documented, open-source, and ideally use a standard encryption protocol. Being able to say "this is exactly how encryption works" in a system is important, and I'm glad you're asking these questions.
Encryption in Blockstack apps is performed client-side via library calls in blockstack.js (our javascript library). The encryption routines are implemented here [1], and implement ECIES, using the user's application-specific private key. That private key is passed to an application during the application authentication process [2]. All a blockstack application has to do is pass { "encrypt": true } in the storage routines, and this is invoked.
We definitely would like to provide better documentation and messaging around how applications engage and use our client libraries -- and documenting our encryption routines is part of that. However, in the meantime, you can feel free to check out or codebase (it's all open source), and we'd always welcome any kind of feedback!
[1] https://github.com/blockstack/blockstack.js/blob/master/src/...
[2] https://github.com/blockstack/blockstack.js/blob/feature/aut...