FIPS 140 compliance for encrypted files Does FIPS 140-2 require specific key sizes, or does it have specific requirements for the data?
In other words, if I encrypt a file, how I can check whether it is FIPS-compliant or not? Does only the key need to be checked, or does the encrypted file have to be checked too? If yes, is it possible to elaborate on how to check an encrypted file for FIPS compliance?
FIPS 140-2 only certifies cryptographic modules, not entire systems. So, to tell if your system is 140-2 compliant, it must be using a 140-2 certified module. NIST publishes a list of all FIPS 140-2 certified cryptographic modules.

It is important to remember, though, that 140-2 certification does not certify that the module is used in a secure manner. From the FIPS 140-2 document:


  Similarly, the use of a validated cryptographic module in a computer or telecommunications system is not sufficient to ensure the security of the overall system.


Looking over the document, I don't see anything on specific key sizes. It discusses key management, including key storage. So you'd have to make sure keys are stored properly. I don't see anything in the document about requirements on the data which is to be encrypted. That makes sense though as you would want your module to be data agnostic.

So, there is no way to look at an encrypted file and tell if it is FIPS 140-2 compliant. You would have to look at the module that did the encrypting.