Kasper 5.0 for Mac could be downloaded from the developer's website when we last checked. We cannot confirm if there is a free download of this app available. The program relates to Security Tools. The actual developer of this free software for Mac is Greg Esposito. According to the results of the Google Safe Browsing check, the developer's site is safe. Despite this, we recommend checking the downloaded files with any free antivirus software.
From the developer:
Kasper is designed to assist in the recovery of password-protected Stuffit archives. Stuffit X archives (denoted with .sitx) utilize greater compression and encryption than .sit and is the current Stuffit standard. There exist password changing software for the original Stuffit 1.5 archives, but the methods used do not work on more modern archives.
You may want to check out more software for Mac, such as PasswordVault Lite, which might be related to Kasper.