"Basically, the NSA asks companies to subtly change their products in undetectable ways: making the random number generator less random, leaking the key somehow

"Basically, the NSA asks companies to subtly change their products in undetectable ways: making the random number generator less random, leaking the key somehow, adding a common exponent to a public-key exchange protocol, and so on. If the back door is discovered, it's explained away as a mistake." I have to wonder if, maybe in some instances, this is why it takes so long for some vendors to patch the vulnerabilities in their software. Maybe some of the problems we report were really there intentionally?