CPU

Poor performance generating entropy in a VM from /dev/random

Just recently a few colleagues of mine were attempting to generate new private keys with a 4096 bit size but they were seeing shocking performance from all of their Linux VMs. They were seeing key generation taking up to 15 minutes while smashing away at the keyboard to generate entropy. It wasn’t a resource issue, the VMs were sized appropriately and showed no signs of stress. They asked me if they could throw a “Chaos Key” USB device into each of the ESXi hosts to generate more entropy to reduce the time it takes, but I knew that wasn’t required (like I was going to let that happen).