I'm not sure if it was what OP meant, but it's arguably a good availability technique (as long as you can generate the checksum, that is). Like, if I want to run custom firmware and flash it, having a checksum which verifies that the firmware isn't corrupted may help prevent bricking.
Right, I'm not sure either. Hence the question. :)
Checksums are great for helping to validate data integrity. And data integrity can be related to security.
But over the last 25 years or so, I've grown to become pretty averse to phrasing that parse like "for security purposes".