That is another example, yes. But the NSA purposely dictated that DES use 56 bit keys (a strange choice of key length to begin with), so that it would be possi

That is another example, yes. But the NSA purposely dictated that DES use 56 bit keys (a strange choice of key length to begin with), so that it would be possible for brute force attacks using government mainframes. The original proposal was for 128 bits IIRC. This was way back before many people studied cryptanalysis, which is why no one cared at the time.