Thanks for just ignoring my question - THERE IS NO ENCRYPTION IN THE ORIGINAL ARTICLE, so WHY are you restating that encryption is involved at all?
Straight from the original artical:
hashed_password = scrypt(password, salt + pepper)
or hashed_password = scrypt(scrypt(password, salt),pepper)
Absolutely zero encryption going on here. Therefore, no ability to "decrypt" the pepper result. The pepper IS NOT a key for encryption. Period.