The horse has already left the barn.
Right here on this computer, I have the source code for BlowFish, a powerful 256-bit encryption algorithm. I could compile it into a library, and use that library to write an application that has uncrackable encryption. Hundreds of thousands of other programmers around the world could do the same thing.
How does the FBI, or anyone else, propose to stop this?
Yeah, but if you have the Blowfish source code - which had an integer signing bug in it for 10+ years that nobody had caught - it doesn’t mean that you KNOW if what you are sending is secure. All those libraries and encryption in general is “magic” to most people.
Blowfish has been broken by NSA a long time ago.
So has AES which is why the NSA allows it.