What is the file "signature.asc" attached to email I receive from Kraken?

The signature.asc file is a PGP signature generated using both the content of the email and Kraken's PGP private key.

It can be used to verify the authenticity of automated emails.

Note: Emails signed using our public key for exchange@kraken.com are sent from noreply@kraken.com.

Instructions:

How do I verify emails from Kraken? (Enigmail)

How do I verify emails from Kraken? (GPG Mail)