These instructions pertain to R6 releases of LS-DYNA.   

1.  To encrypt a portion of your LS-DYNA input data, 
you will need a working copy of GPG, a freely available public
key encryption program.  If you are running on a Linux machine, it is
probably already installed.  If you need a copy, you can get one
from www.gnupg.org
(NOTE: Windows users, see note at bottom on command to encrypt
a file.)

2. Cut and paste the public key block (listed below) to a file.
Include the "-----BEGIN" and "-----END" lines in the file!


-----BEGIN PGP PUBLIC KEY BLOCK-----
Version: GnuPG v1.4.2 (GNU/Linux)
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=6VsN
-----END PGP PUBLIC KEY BLOCK-----


3. Import the key.  
If using GPG from the command line, type   

gpg --import <filename>"

where "<filename>" is the name of the file you saved in step 2 above. 


4. Now you're ready to encrypt input data for LS-DYNA.

Create a file (herein called "input" for sake of example) that contains the block of
keyword input that you want to encrypt.  
Encrypt it by typing the following command line:

gpg -e -a --openpgp --textmode --cipher-algo AES  --compress-algo 0 -r 0x3B30B003 input 

This will create a file "input.asc" which can be included in your  
main LS-DYNA input file using the *INCLUDE command.



Background:
The idea for GPG is that you use someone else's (here, LS-DYNA's) public key to send a message to them, 
and they can decrypt it using their private key. See
http://en.wikipedia.org/wiki/Public-key_cryptography
So it follows that all you need to do is to encrypt the input deck using  
LS-DYNA's public key, and LS-DYNA will read the encrypted deck and unencrypt it internally.

_______________________________________________________
 
An enhancement to encryption is the ability to suppress
all output for a subset of parts.
By invoking input encryption and output supression together, 
it's possible to hide the geometry, material, etc. of specified parts  
from another analyst yet allow that analyst possession of the input so that he might
modify or add to unencrypted portions of the model and run analyses.   
PSETID in *database_binary_d3plot identifies 
the part set containing the parts to be omitted from
all output including d3plot.  By including *database_binary_d3plot with a 
nonzero PSETID in an encrypted portion of the input, a safeguard in
invoked that prevents PSETID from being reset elsewhere in the input.

An example in which one part (part 500) is so hidden is provided in
http://ftp.lstc.com/anonymous/outgoing/jday/encrypt.tar.gz

________________________________________________________

Q:  When I encrypted my test file I got this warning:
"There is no assurance this key belongs to the named user"
Is this normal?

A:  That is generally nothing to worry about.  If you were to read all the 
documentation that comes with GPG and understand the public key/private key 
web of trust model, all this would become clear.  
The guy who designed PGP (on which GPG is based) was, rightly so, quite picky 
about security.  So unless you 'sign' the key, swearing you have verified, personal, 
first hand knowledge that in fact that key belongs to the user you think it does, 
it is going to complain about it.  In an ideal world, you would have received that key, 
in person, from someone you trust here at LSTC.  But you aren't trying to communicate QUITE 
as securely as all that.  Before you trust it with some really sensitive data, you should 
verify the key fingerprint with someone you know here at LSTC (email doesn't count -- it can 
be intercepted or forged!).  But again, for our applications that much security 
is probably not necessary.
So yes, given the circumstances, it is normal. 
_______________________________________________________________

Internal Note:
To embed an expiration date in the encrypted data, see the notes
in "expire.encrypt".


______________________________________________
For Windows Users:
I did install Gpg4win. The gpg2.exe is in c:\program file (x86)\GNU\GnuPG\ folder. Please try use command line:
 
c:\program file (x86)\GNU\GnuPG\gpg2.exe -e -a --openpgp --textmode --cipher-algo AES --compress-algo 0 -r
0x3B30B003 input

Guanhua
11/2/11
______________________________________________