verilogA encryption for spectre

Hi Fabrice

You cannot use spectre_encrypt on a veriloga file. You will need to use ncprotect. Would you please refer to COS article 11203304 for more details?
unix> ncprotect -extension vap -language vlog -autoprotect mymodule.va

The above command will encrypt the "mymodule.va" file and create a new encrypted file called "mymodule.va.vap".

 Thank you very much, it works perfectly.

regards,

fab

Hello Quek,

I have used your method to encrypt my file "veriloga.va", it works well. However I don't understand why because we didn't set a password, and we can always open the ".va" file freely, it hasn't been encrypted. Could you please explict it to me? Thank you.

Best regards,

UU

I don't understand your question - you said it works well, and then said that it wasn't encrypted. Presumably it can't be both? The original file does not get encrypted - it leaves it as is. You end up with an encrypted file with the suffix ".vap" with the instructions that Quek gave - and this is using the standard Cadence key (keyname CDS_KEY). It's possible to use other key pairs - search in the INCISIVE documentation using cdnshelp for "-rsakeygenerate" and more details can be found on how to manage a key database.

Regards,

Andrew.

 Thank you for your reply. I meant that the instruction can be executed and ".vap" file and ".log file " are created but the original file does not get encryted. What do you mean by "INCISIVE documentation", I have found the words "encryption", "encrypt", "key", "protect" etc. in the "virtuoso documentation " in "help", but I found nothing. Do you know why? Thank you.

Regards,

UU

The original file is not supposed to be touched - the .vap file is the encrypted equivalent of the original file - so you could use that wherever you were using the VerilogA file. Most encryption tools work that way (e.g. pgp, gpg) - they leave you the plain text file because that's probably your master file and you don't want to lose it!

The "ncprotect" command is supplied in both the MMSIM stream and the INCISIV stream (which is where the digital and mixed-signal simulators live). There is some documentation in the MMSIM stream - so if you run `cds_root spectre`/tools/bin/cdnshelp and then search for "ncprotect" you'll find some information. If you have the digital or AMS simulators installed and in your path, there's more information in the INCISIV stream documentation - so run `cds_root irun`/tools/bin/cdnshelp and search for "-rsakeygenerate". That's only if you really need to have specific public/private key pairs, which is quite possibly overkill for what you need - the default behaviour (as I said) is to use a Cadence key.

Regards,

Andew.

I have found "ncprotect", and did the encryption. However, ".vap" can't be used for simulation, do you think it's normal or not? If it can't be used for simulation, the encryption will be unuseful.

Regards,

UU

 Why can't it be used for simulation? From the command line, using this in a spectre netlist:

ahdl_include "mymodel.va.vap" 

works fine. If you want it to be in a veriloga view inside  a Virtuoso library, there's nothing to stop you renaming the ".vap" to "veriloga.va" - it will still work OK. There's nothing special about this .vap suffix.

Regards,

Andrew.

 I have deleted ".vap" and it works well. Thank you very much for your help.

Hello there,

I have encrypted a simple verilog file using "spectre_encrypt" command.

When i try to simulate it using "spectre" , it gives pragma error.

ERROR (VACOMP-1588): "verilog_enc_line.v", line 12: Could not decrypt the encrypted file.
invalid or unknown or incomplete pragma specification 'NO ERROR'
Check that the encryption key is valid and that the version of the encryptor for this file is compatible with (not
newer than) the version of the decryptor.
ERROR (VACOMP-1588): "Error: unexpected EOF or end of line//pragma protect begin_protected"
"verilog_enc_line.v", line 13: Could not decrypt the encrypted file.
invalid or unknown or incomplete pragma specification 'invalid or unknown or incomplete pragma specification 'NO
ERROR''
Check that the encryption key is valid and that the version of the encryptor for this file is compatible with (not
newer than) the version of the decryptor.

My "run Simulation" file looks like below.

rsim (a b) simpleres
simulator lang = spectre
ahdl_include "verilog_enc_line.v"
tran tran stop=10n errpreset=conservative write="spectre.ic" writefinal="spectre.fc" annotate=status maxiters=5

Any help is appreciated.

Thanks & Regards,

Amar