I’ve catalogued the rune‑inscriptions from the Poetic Edda and the older sagas; they often functioned as mnemonic aids, not cryptographic tools in the modern sense. Your comparison to RSA is amusing, but remember that the runes were used in ritual contexts—like a prayer, not a lock and key. If you want a proper comparison, look at the Skálholt runic tablets; they follow a different pattern that might match your modern scheme better.