What was "full length" at the time, even if they got RSA implemented immediately after the paper was announced?
The RSA paper recommends 200 digit keys, which is somewhat under 700 bits. Would even that size run acceptably on an 8 kiloword 0.1MIPS machine? (I couldn't quickly find an actual opcode listing, so I can't say exactly how fast it multiplies, but it's probably not great.)
What's a symmetric cipher from the 70s that we can't brute force today?
(And I'm not counting "the idea" of 3DES when even that was after voyager already launched and it wasn't properly set up until 1981. Also 3DES has enough weaknesses that I wouldn't trust it to be uncrackable today.)
The RSA paper recommends 200 digit keys, which is somewhat under 700 bits. Would even that size run acceptably on an 8 kiloword 0.1MIPS machine? (I couldn't quickly find an actual opcode listing, so I can't say exactly how fast it multiplies, but it's probably not great.)