This is Oscar 0.5.2, a security release for Oscar 0.5.
Insecure use of SECRET_KEY in basket cookie
For anonymous users, the basket ID is stored in a cookie. Previously, the
value was signed using a simple CRC32 hash using the SECRET_KEY.
However, a good rule of thumb is to never roll your own encryption, and it is
possible that this method weakens the security of the SECRET_KEY.
The fix uses Django’s cryptographic signing functionality to sign the cookie
in a more secure manner.