Sentence Iota Seeds
The full article was originally published by Eukaryote on Medium. Read the full article here.
Yes, it may be hard (admittedly, currently impossible, but with a considerably smaller margin than a random seed) to exploit this presently, but really, using a random seed stored in a password-encrypted file on your computer is much safer than a sentence seed and isn’t really that much more effort (typing out a seed is, in fact, is quite a laborious task!).
But just how much less secure? There are 8.71*10¹¹⁵ possible random Iota seeds if you generate it randomly. Since the information density of an English sentence is about 1.2 bit per character, there are only 2⁹⁷ possible sentence seeds, which is about 1.82*10²⁹. Even adding an extra 20 bits to account for typos, foreign words, proper nouns, minor variations, etc, that’s still only 1.9*10³⁵ total IOTA seeds. That’s 456,825,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000 random seeds for every sentence seed!
TL;DR While Iota seeds containing sentences are indeed currently secure, it leaves very little headroom for potential future cryptographic weaknesses or better natural language prediction techniques or social engineering (us humans are quite a predictable bunch! examples: keyboard mashing is surprisingly predictable, our random number generation is horribly skewed, and, indeed, our ability to pick random objects in general is quite non-random, to say the least.) or many other potential, currently unknown threats that may potentially lower the security of seeds slightly. Given that a purely random seed isn’t really that much harder to use anyways, there is really no downside; and it just might save your money someday.