📝How-to: read entropy available

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#how-to

Entropy is an estimate of the number of bits of entropy in the pool (max 4,096 in linux). If the number is below 200, that’s bad.

cat /proc/sys/kernel/random/entropy_avail

If entropy is below 160(?) (length of sha-1 hash), reading from /dev/random will block until more entropy is available.

Resources:

• Ensuring Randomness with Linux’s Random Number Generator