Category: Encryption / Decryption
GnuPG – Public / Private Key Method – Encryption / Decryption (No Digital Signature)
<When You Encounter This Error Don’t Panic>
GPG key generation: Not enough random bytes available.
Not enough random bytes available
Generating keys with GnuPG
Anyone who wants to create a new key set via GnuPG (GPG) may run into this error:
We need to generate a lot of random bytes. It is a good idea to perform some other action (type on the keyboard, move the mouse, utilize the disks) during the prime generation; this gives the random number generator a better chance to gain enough entropy. Not enough random bytes available. Please do some other work to give the OS a chance to collect more entropy! (Need 142 more bytes)
The problem is caused by the lack of entropy (or random system noise). While trying to get more, you might keep running into this message. In our case running a find on the disk, while making sha1sums and putting that into files, was actually not enough.
To check the available entropy, check the kernel parameters:
cat /proc/sys/kernel/random/entropy_avail 36
To solve it, run the rngd command: rngd -f -r /dev/urandom
Debian / Ubuntu: apt-get install rng-tools
Red Hat / CentOS: yum install -y rng-utils
Checking the available entropy again revealed in our case a stunning 3100, almost 100 times more than before. GnuPG is now happy again and can finish creating the keys.