One of the neater bits of world building/subplots in the book "A fire upon the deep" is their ship is a freighter with a cargo full of one time pad keys. that i

One of the neater bits of world building/subplots in the book "A fire upon the deep" is their ship is a freighter with a cargo full of one time pad keys. that is, the encryption you would revert to in a world where factorization is easy.