# How many times can a key be used for HMAC-SHA256 before it needs to be rotated?

If I wanted to use hmac for proving that a value hadn't been tampered with, how many times can I use a key before it needs to be rotated?

• Thanks. So basically with a good key from something quality like /dev/urandom I should be good to go. – mr blobby Dec 23 '14 at 23:49