Why the NSA Called Me After Midnight and Requested My Source Code

medium.com

33 points·brunoluiz··9 comments

Previous discussion: https://news.ycombinator.com/item?id=18293940

Strange that they would need the source code. I would think that it should be easy to figure out what encryption algorithm it uses by looking at the binary if it wasn't blatantly advertised anyway.

one guess might be they wanted to know exactly how the software seeded the PRNG, to cut down their search space dramatically.

The binary would tell them that - in fact, it'd tell them that better than the source if there were any overlaps into garbage memory for example.

Wanting the source is purely for speedy analysis.

I've never done windows (95?) disassembly, but from what little VSC++ I did back in the day, for the sake of speed, I would probably have wanted to see the source code instead of disassembling! Don't know how good at this stuff the NSA was back then.

They may not need it, but source code will allow them to read it faster and with a higher chance of getting it right.

It will also make it easier to re-run the decryption routine to get the original file/verify a cracking attempt instead of having to reimplement it correctly (possibly without having known-good test vectors to check if they got it right).

I expect what he wanted was the data structures. You know — length field at the start, then foo, then bar, then payload data.

(I've never broken "real" encryption, but I spent quite some time during my teens on, ah, improving the user-friendliness of computer games.)

Why is it midnight when the NSA calls, in Connecticut (EST), and 1AM when he calls to his partner, IN CALIFORNIA, for the source code?

Must have been 4 hours later?

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