> for instance with the SIMON/SPECK block cipher designs --- block ciphers, after all, are the lynchpin of secure systems. The lynchpin to ciphers are the keys

> for instance with the SIMON/SPECK block cipher designs --- block ciphers, after all, are the lynchpin of secure systems. The lynchpin to ciphers are the keys. That's the very definition--proof of security reduces to the question of whether you know the key or not. Unless you exchange a database of one-time pads, you invariably need an RNG to generate keys for your ciphers. That's your lynchpin right there. The key is the lynchpin, and RNGs generate your keys. You don't need to feel it; it's cryptography 101. Granted, it's such a basic and fundamental aspect to secure systems that it usually gets lost in all the bike shedding.