I would argue that in the last 15 years he has gotten further from the vanguard of encryption, purely by virtue of the field advancing. I don't think an age li

I would argue that in the last 15 years he has gotten further from the vanguard of encryption, purely by virtue of the field advancing. I don't think an age limit makes sense though, as his knowledge of encryption is not likely to be any worse than the vast majority of the population anyway.