That seems really unlikely to exist. I don't recall any encryption associated with STEP files. I suppose one could use ZIP or Windows encryption which does allow password protection, but as soon as that is unencrypted it's free-range.

SW native files can be encrypted as there is only one application that is designed to read them so coordination is easy. STEP was designed to be opened by any CAD, CAM, or QC program and they may not have any encryption management.

Thanks, 3DDave.

A quick question then: Is encrypting a file the same as setting up a password to open it? I thought these are two different ways of securing a file.

Not much point to encrypting a file if anyone can just unencrypt it without a password. Also, the OS is able to open the file without a password in order to pass it to the program asking for the password. If the OS can do that, then the OS is usually able to pass that same file content to a program like Notepad. If it's not encrypted then a password does no good.

A bit more - It is typical that a file that is marked inside the OS as password protected has this managed by creating a file pointer record in the file lookup table (the table that converts file names into locations on the storage media, whether a rotating disk or a sort of simulation of it provided by solid state drives.)

This avoids modifying the file itself in a way that would either require pre-pending the password or suffixing the password to the file, in addition to the flag in the file lookup table to show the file has a password. It's bad to alter the file and file modification dates for a change in password.

There is a trick though - Windows can encrypt a file, but since it knows the original creation/modification dates, it will report those as the encryption is reversible and doesn't, to the user, alter the content.

Windows however, doesn't store a password in a readable form. They send the password you type into a "hash" function that converts the password though a lengthy formula into a code. This hash is such that no two passwords will have the same hash result and that passwords that differ by only one character have hashes that are nowhere close to each other, so guessing a password and seeing the hash and comparing it to the target doesn't help.

As far as I can see the only option for Windows is Encrypt with Password.

A STEP file is just a text file. You'll need a 3rd party tool to wrap encryption around it (ie. ZIP, etc). There's also steganography but that's more about hiding a file.

<tg>

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Thanks, 3DDave, for the detailed explanation. Appreciated.