If you use a downloaded key for your own data encryption, you are using a key that is publicly known. This completely invalidates the security of your encryption , as anyone with the same file can decrypt your data. How to Safely Generate Your Own Key

If you want, I can:

may use binary files for public key digests during secure boot or flash encryption processes. Security Best Practices

As Jack continued to investigate, he discovered that the website from which the file was downloaded had been compromised by a sophisticated threat actor. The website had been serving malware-laced files to unsuspecting visitors.