Compatibility between Silver Key versions
Silver Key 5 introduced a new parcel format – more secure and tamper-proof, offering a lot of new features.
There is a drawback, though: older Silver Key versions don't know anything about this cool new format. If you try to decrypt a version 5 parcel with an older Silver Key version, you will see this message box:
This message means that the installed Silver Key version can't recognize the format of this new-style parcel, which needs a newer decryptor.
What Can Be Done Here?
There are several ways to solve this problem:
A rather obvious solution and also the best one. However if upgrading is out of the question, there are other methods.
Using self-decrypting parcels
Self-decrypting parcels contain an embedded decryptor and so have no compatibility problem. You can create self-decrypting parcel in several ways; the simplest one is the Explorer's right-click command Create EXE Parcel.
Using compatibility mode
Silver Key 5 can create old-style parcels that can be decrypted by older versions if you switch it to the compatibility mode:
Double-click Silver Key desktop icon and press 'Settings'. Select the 'Cipher' page; in the drop box 'Engine to use' select 'Silver Key 4.x compatibility' (or 3.x if the target version is really old). Press OK. Silver Key will now produce old-format files, decryptable by older versions.