Oh, there are definitely better ways to de-bias; the read-check-discard construction is meant as a math example, not practical advice. Most of the popular PRNG

Oh, there are definitely better ways to de-bias; the read-check-discard construction is meant as a math example, not practical advice. Most of the popular PRNG constructions (for instance, anything in SP800-90A) will integrate things in a much saner fashion (e.g., with a hash or MAC algorithm). I was mainly trying to make the point that a bias in a random bit source doesn't automatically mean that everything is broken and horrible. The biased/low-entropy point was mainly in relation to a specific case mentioned in the original article (Allwinner embedded ARM systems). I don't know how quickly that particular HWRNG provides data, but if the bias isn't huge, and the random can be read quickly enough, I'd probably argue to include it. Even if it's biased 4-to-1, you can still reach a desired "amount" of randomness (however you're choosing to measure it) pretty quickly.