Question

Is there a way I can Convert my Lockbox 2 Cipher text to LockBox 3 Cipher text.
We are migrating our application built on Delphi 2007 to Delphi xe2, we used the Lockbox 2 RSA Encryption algorithm in Delphi 2007 and we intend to use lockbox 3 in Delphi xe2 to support Unicode data. since the cipher text generated by both of them differs as Xe2 supports Unicode data we face a problem . So we would like to convert the cipher text that is generated by Lockbox 2 to LockBox 3 somehow.

Answer 1

Since your cipher text by definition is unrecognizable, there is no easy way to tell if the underlying plaintext data was Ansi or Unicode….so you likely need to manage a new associated property.

It obviously depends on the layout of your application and where this data is stored and how the clients are going to be upgraded, but there could be a new version flag of some sort associated with the stored ciphertext. If it’s in a local table say, add a new column for PlainTextVersion and set the version to some value to flag that the ciphertext was saved from Unicode plaintext. When reading the ciphertext and this new field doesn’t match the Unicdoe flag, you could upgrade the ciphertext by decrypting, and encrypting using Unicode plaintext, and then re-save the ciphertext and set the new flag (or simply put-off the ciphertext version upgrade until the plaintext has changed and needs to be updated.)

Or, better yet, auto-upgrade all current ciphertext at one time if feasible.