MATLAB: Pcode with user-provided key

MATLABoptional parameterpcodeuser key

We're using R2012a, in case that plays into your answer.
Our project's source fileset has been backed up at intervals, but despite that, at least one m-file has gone missing from the current fileset and all backups. A p-file exists. I have read the Community posts about de-obfuscation and totally get the reason for the absence of such a function as long as the MathWorks has sole access to the encryption key(s).
My question is, why isn't there a form of pcode that allows the caller to specify a key or key pair, so that those who have been given a key by the code's developer can analyze the pcode and at least partially restore the source code and symbol definitions? If that had been available, I'm sure my PI would have used it, and our task of restoring the function would be much easier.
Doug

Best Answer

It is very easy to create such files with a specified key: Simply use a zip or 7z format with an encryption key. Then you can restore the original file even with comments and without loosing any information.
A user provided key inside the P-file is not useful: If the key is a part of the file, it does not matter if Mathworks or the user provides it. In both cases it can be extracted by the same trivial method.
Nothing is as reliable as a working backup system. User provided keys for a proprietary file format with a high degree of obfuscation are not a trustworthy system for a file recovery.
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