[mitchtbaum]

Ah.. Now I get it.

So, if each branch's code was signed and contained an embedded key and chosen encryption algorithm, then if the app used those during processing and users received verifiable transmissions, that app's output could be verified by users as having come from that advertised branch.

[mitchtbaum]

http://en.wikipedia.org/wiki/Code_signing seems relevant. This case is more about having the software itself sign its own output. Relevant search terms:

* software "sign its own output"

* software "encrypt its own output"

* software "encrypt its output"

* software "sign its output"

Some interesting results:

* Computer scientists develop 'mathematical jigsaw puzzles' to encrypt software (UCLA) #comment by zblaxell http://lwn.net/Articles/562113/

* Cryptographic Verification of Test Coverage Claims http://www.cs.ucdavis.edu/~devanbu/doc.ps

* Study of Security in Multi-Agent Architectures §3.4 http://www.ecs.soton.ac.uk/~lavm/papers/sec.pdf