NSA still has the secret Suite A system for their most sensitive information. If they think that is better than the current public algorithms and their goal is to make telecommunications vendors to have better encryption, then why doesn't they publish those so telco could use it?
> Truly, truly can't understand why anyone finds this line of reasoning plausible. (Before anyone yells Dual_EC_DRBG, that was a NOBUS backdoor, which is an argument against the NSA promoting mathematically broken cryptography, if anything.)
The NSA weakened DES against brute-force attack by reducing the key size (while making it stronger against differential cryptanalysis, though).
https://en.wikipedia.org/wiki/Data_Encryption_Standard#NSA's...
Also NSA put a broken cipher in the Clipper Chip (beside all the other vulnerabilities).