Micro-Cap 11 can encrypt not just macros, but library files as well.
Most commercial modeling is done in the form of subcircuits which are
saved in text files. Here, for example, is a portion of the analog.lib
provided by Spectrum Software as a part of the Analog Libraries:
The file is not encrypted. You can see the contents and create a circuit
diagram of the models. If you are a semiconductor manufacturer and these
models describe what you feel is proprietary to your company, you might
want to encrypt them to protect your intellectual property. Here is how
you would go about encrypting the file.
1) Load the file using the File Load command.
2) Select the File menu Encrypt / Decrypt option. That invokes the
Encryption dialog box. It looks like this:
To encrypt the file simply enter a password. Enter it again to be sure that
the password you want to use is entered. Click on the OK button.
Micro-Cap encrypts the critical portions, leaving the headers intact.
This is done so that you can see the pin names and any possible parameters
used by the subcircuits. The encrypted file is saved to disk. It looks
like this:
The critical parts of the subcircuit have been encrypted leaving the
comments and the .subckt line intact. That way you can see the pin
names (which are needed when the part is entered into the Component
library) and parameters (which are needed when you place the part
in a schematic), and the comments (which are helpful in understanding
the pin functions and parameters).
When Micro-Cap analyzes a schematic containing an encrypted part, it
decrypts it and parses the contents as it would for an un-encrypted
part. The contents just never get displayed.
To decrypt a library file, load it, then select the Encrypt / Decrypt
item from the File menu. Enter the password. Click OK. The program
decrypts the entire file, saves it to disk, and displays the file in
pain text.
Macros are handled somewhat differently because it is necessary for
the user to be able to view partially encrypted library files but not
so with encrypted macro files.
To encrypt a macro, do this:
1) Load the macro file using the File Load command.
2) Select the File menu Encrypt / Decrypt option.
3) Enter the desired password twice.
4) Click on the OK button.
The program encrypts the macro file, saves it to disk, and removes
the file from memory. If you subsequently load the file, the program
will ask for the password. If you enter the password correctly,
the program displays the file. It does NOT save the decrypted file
to disk. To do that you must use the File menu Save or Save As
command.
To decrypt an encrypted macro file do this:
1) Load the macro file using the File Load command.
2) Enter the password.
3) Optionally use the Save command to save the decrypted file to disk.
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