[ardy42]

> The NSA used to have a defensive mission.

The NSA still has a defensive mission, and it hasn't changed. It just might not be the defensive mission you assumed it was. IIRC, it's mainly to defend US Government systems and communications from adversaries. To the extent they help with the defense of civilian systems, their goal seems to be to give them adequate security, not absolute security.

For instance, take this episode from the development of DES during the 70s:

https://en.wikipedia.org/wiki/Data_Encryption_Standard#NSA's...

> NSA worked closely with IBM to strengthen the algorithm against all except brute-force attacks and to strengthen substitution tables, called S-boxes. Conversely, NSA tried to convince IBM to reduce the length of the key from 64 to 48 bits. Ultimately they compromised on a 56-bit key.