Using IEEE Standard Encryption for VHDL-AMS Models in Twin Builder

Twin Builder Encryption Public Key

Apply IEEE standard encryption to a VHDL-AMS model with the following Twin Builder public key:

Twin Builder Command-line Encryption Tool

In a Command Prompt window, enter:

<Ansys Twin Builder install path>\TwinBuilder_encryptvhdl.exe <source file>

Limitations

• Ansys Twin Builder only supports encrypting the entire architecture of the model.
  The `protect directive must be inserted just after the architecture definition, that is, architecture <behav> of <entity>.
  The `protect end directive must be just before the end architecture statement.
• Ansys Twin Builder only supports the `protect begin and `protect end directives. No other `protect directives are supported and will cause an error to be output by the encryptor.
• The Ansys tool will, by default, generate encrypted session keys for Twin Builder.
• Ansys Twin Builder only supports the aes-128-cbc symmetric encryption algorithm for encrypting the model.
• Ansys Twin Builder only supports the RSA asymmetric encryption algorithm for encrypting the session key.

Decryption in Twin Builder

Ansys Twin Builder supports decrypting models that have been encrypted using the Ansys Twin Builder public key above. The workflow has been tested with the Twin Builder encryption tool as well as the Mentor Graphics^® encryption tool.

Limitation

Ansys Twin Builder does not support Section 9, standard 1735, Visibility management, of the IEEE Recommended Practice for Encryption and Management of Electronic Design Intellectual Property (IP).

When you load an encrypted model (regardless of the tool used to encrypt the model) into Ansys Twin Builder:

• Ansys Twin Builder does not hide names inside the protected part of the model.

• Ansys Twin Builder does not hide hierarchical paths through the protected part of the model.

• If an error or warning is generated from inside the protected part of the model, Ansys Twin Builder may include references to protected names as well as to original file line numbers.