Encryption

Encryption functionality is available in OptiStruct input files to encrypt confidential information.

There are two methods available for encryption. With Method 1, You can encrypt a full line or only certain fields in a line; with Method 2, you can encrypt entire include files (which contain entries supported for encryption). Currently, material, property and some table Bulk Data Entries are supported (see Supported Entries).

Method 1: Encrypt Lines or Fields in a Line

Encryption Key

A typical encryption key is shown below. The first line contains the label ‘/ENCRYPT/’ and a unique encryption ID following it. The subsequent 5 lines are the encryption key required to decrypt the encrypted lines.

The encryption key(s) could be placed in either Case Control section or Bulk Data section, but it (they) must be placed before the corresponding encrypted lines. Up to 100 different encryption keys are allowed (including those in the include files).

Example Encryption key with ID ZB001:

/ENCRYPT/ZB001
1GcxRn2nMRIp575cxxQrdIBaZYBB6oPGNhPJh4lAZOH9HdVivEeMVIGEJWJM5T0q6O3zzUH3KyJRJ5OOjx6ojdd9OjHT4C63ko2I
%ZB001MGoRMaLooUWUaHxbHHbErfqmYfVVMh9h2TgKcZvYw13940WzdJv0cS2KuK77XBDGBvyMtNikHbfwlaasrGdSkKAZZrEdrP
%ZB001gbGGRgQ0GQMCYNi4HIdcbTbCFWcJDnCH7UfhSwwjZTammusHl9juHaAT5pxPeNVdkwv9OqH44OTmv5XeiD1uaSxTNH2u8i
%ZB001P0av0XqspIeqUWja5CVLjvismTRhTLOPOmTJyK3FPyeh77evhjFZxmANrKrdXpoML6xTMkK8emlwoN9vYumaBvqRLsg8zs
%ZB001H80ZXXnnhZ6cViaSBly3G4xhptIpGKWYjyXThW7R1ERUrmBjxBq7mpKX5hno4LdLitUvMUjOlSFJYy507eyyakjnKtzvU7

Encryption Process

Encryption can be applied to full lines of numeric data or partial lines by choosing a few fields in a line. Specific entries (and the corresponding data on such entries, like MAT1), should be identified and such entries can be listed in an ASCII file. The encryption tool included with the Solvers package can then be used to encrypt the lines listed in the ASCII file. The encryption tool is included in the following locations in the Solvers installation:

Windows:
$ALTAIR_HOME\hwsolvers\optistruct\bin\win64\os_encrypt_win.exe
Linux:
$ALTAIR_HOME/hwsolvers/optistruct/bin/linux64/os_encrypt_linux

The following example illustrates the process of encrypting some material data in an OptiStruct input file.

Example:

In the non-encrypted OptiStruct input file (input_file.fem), if you have the following MAT1 entry:

MAT1    120     1.E6          0.0     3.57      1.0e-4 
        35.E3   35.E3   23.E3

Specify the following lines to encrypt all fields except for the MAT1 entry name and ID, then, in an ASCII file original.txt:

                 1.E6         0.0     3.57       1.0e-4 
        35.E3    35.E3  23.E3

The MAT1 entry name and ID have been removed, as shown above.

Next, the encrypted lines for the values/fields listed in the original.txt file could be obtained by running the encryption tool as follows:

On Windows, the os_encrypt_win.exe encryption tool can be used to encrypt lines, using the following example command:

os_encrypt_win.exe original.txt encrypted.txt

On Linux, the os_encrypt_linux encryption tool can be used to encrypt lines, using the following example command:

os_encrypt_linux original.txt encrypted.txt

After the encryption tool runs, the file encrypted.txt, will contain both the encryption key and the encrypted lines, as the following example data.

/ENCRYPT/SA001         
8C6E0qxlqRSurzdzpaFk93kzJLuCxSAYseqRhFPBFaG1SoOJRDDyynNiaZjSEUHjRBqStVSYhQRM5ry8M0kJ1rJIvDO3k8w5SDXL
%SA001MGoRMaLooUWUaHxbHHbp7O3cswgTiO9703TesSogWarRCwQe5p9MfSXRsaWT357uMSIWQAJCJOk2c52pyVLF5mXFLIhBmu
%SA001gbGGRgQ0GQMCYNi4HIdIoVBlaqZl3n58MMkJ0779RKgMC84EVxFYcsxsLNe3SZhZDlXbDvAoOTqA4sHt7k1zDCcYYF96hr
%SA001P0av0XqspIeqUWja5CV1wxIR7nO9JLHGdeYvWVEfHpkHXLqsRXlDI4xm7sYHL10IovZvBpDsyr8KxAtAxRmfofOIIcZ6Kn
%SA001H80ZXXnnhZ6cViaSBlymF2Pj1cig3W04EcOn11EaAUV2FyLefxKj555uJDSQqVnF9g4L9Xa63VaffjnDU9w1BSMqTp451E 
%SA001CJeM8FK1xQacReDR8E9G5w8BpP1vdbQAEAxSP4fjRVsR6vapexJOzhxqumnfUK6CtDJdkfDRig4EgHO88eVh0fdBk2uunT
%SA001iKC2I3czrRgT6NH18PAmc1t6YoiNWRY1oXKgFH5Q6hfkr6fvqbW9o6MQVtvLqqQoThoECm3LCAjusU9Zj3CMZFJiwxtTMD

Note: The encryption key ID for this example is the keyword SA001 following /ENCRYPT/.

Following this encryption key ID, the first five lines correspond to the encryption key that will be used by OptiStruct to decrypt the encrypted data. The remaining lines (in this case, there are 2 lines after the encryption key), correspond to the encrypted form of the lines that were initially input in the original.txt file.

The encrypted fields in the original input_file.fem file should be replaced by %% for partially encrypted lines. For fully encrypted lines, the entire original lines should be removed and replaced with the encrypted form of the lines.

Note: The encryption key should be in the same input_file.fem file and should be placed above the corresponding lines which are being encrypted.

/ENCRYPT/SA001         
8C6E0qxlqRSurzdzpaFk93kzJLuCxSAYseqRhFPBFaG1SoOJRDDyynNiaZjSEUHjRBqStVSYhQRM5ry8M0kJ1rJIvDO3k8w5SDXL
%SA001MGoRMaLooUWUaHxbHHbp7O3cswgTiO9703TesSogWarRCwQe5p9MfSXRsaWT357uMSIWQAJCJOk2c52pyVLF5mXFLIhBmu
%SA001gbGGRgQ0GQMCYNi4HIdIoVBlaqZl3n58MMkJ0779RKgMC84EVxFYcsxsLNe3SZhZDlXbDvAoOTqA4sHt7k1zDCcYYF96hr
%SA001P0av0XqspIeqUWja5CV1wxIR7nO9JLHGdeYvWVEfHpkHXLqsRXlDI4xm7sYHL10IovZvBpDsyr8KxAtAxRmfofOIIcZ6Kn
%SA001H80ZXXnnhZ6cViaSBlymF2Pj1cig3W04EcOn11EaAUV2FyLefxKj555uJDSQqVnF9g4L9Xa63VaffjnDU9w1BSMqTp451E
MAT1      120          %%                     %%          %%        %%  
%SA001CJeM8FK1xQacReDR8E9G5w8BpP1vdbQAEAxSP4fjRVsR6vapexJOzhxqumnfUK6CtDJdkfDRig4EgHO88eVh0fdBk2uunT
%SA001iKC2I3czrRgT6NH18PAmc1t6YoiNWRY1oXKgFH5Q6hfkr6fvqbW9o6MQVtvLqqQoThoECm3LCAjusU9Zj3CMZFJiwxtTMD

In Encryption Key, (/ENCRYPT/SA001, and the first 5 lines) are placed above the actual lines to be encrypted. Additionally, all the encrypted fields in partially encrypted initial line of MAT1 entry are replaced with %%, and the continuation line of the MAT1 entry is completely removed. The first line beginning with %SA001 after the MAT1 entry above contains the encrypted data for the fields marked with %%, and the second line beginning with %SA001 contains the encrypted data for the continuation line.

Note:

Only numerical fields are currently supported for encryption. Encrypting character data is not currently supported.
Characters, entry names, identification numbers (IDs), and special signs cannot be encrypted. Only partial line encryption can be used in such cases, where these fields should not be identified for encryption using the encryption tool.
Fixed short, fixed long and free format are all supported. A partially encrypted line in long format with two half lines must be followed by two encrypted half lines.

If multiple lines/entries to be encrypted, are run through the encryption tool separately, then multiple encryption keys and encrypted line combinations, corresponding to each line/entry are received. However, the encryption key IDs will be the same. If such lines/entries are to be used in the same model, then the encryption key IDs should be manually changed to make sure that all encryption key IDs, used in the same model, are different.

For instance, if both the following encrypted lines, MAT1 ID 120 and

MAT1 ID
                                    220

, below are to be used in the same model, then the encryption key for the second encrypted material (

MAT1 ID
                                    220

) should be changed manually to a different ID (from SA001 to SA002), as:

/ENCRYPT/SA001         
8C6E0qxlqRSurzdzpaFk93kzJLuCxSAYseqRhFPBFaG1SoOJRDDyynNiaZjSEUHjRBqStVSYhQRM5ry8M0kJ1rJIvDO3k8w5SDXL
%SA001MGoRMaLooUWUaHxbHHbp7O3cswgTiO9703TesSogWarRCwQe5p9MfSXRsaWT357uMSIWQAJCJOk2c52pyVLF5mXFLIhBmu
%SA001gbGGRgQ0GQMCYNi4HIdIoVBlaqZl3n58MMkJ0779RKgMC84EVxFYcsxsLNe3SZhZDlXbDvAoOTqA4sHt7k1zDCcYYF96hr
%SA001P0av0XqspIeqUWja5CV1wxIR7nO9JLHGdeYvWVEfHpkHXLqsRXlDI4xm7sYHL10IovZvBpDsyr8KxAtAxRmfofOIIcZ6Kn
%SA001H80ZXXnnhZ6cViaSBlymF2Pj1cig3W04EcOn11EaAUV2FyLefxKj555uJDSQqVnF9g4L9Xa63VaffjnDU9w1BSMqTp451E
MAT1    120     %%              %%      %%      %%  
%SA001CJeM8FK1xQacReDR8E9G5w8BpP1vdbQAEAxSP4fjRVsR6vapexJOzhxqumnfUK6CtDJdkfDRig4EgHO88eVh0fdBk2uunT

/ENCRYPT/SA002
1GcxRn2nMRIp575cxxQrdIBaZYBB6oPGNhPJh4lAZOH9HdVivEeMVIGEJWJM5T0q6O3zzUH3KyJRJ5OOjx6ojdd9OjHT4C63ko2I
%SA002MGoRMaLooUWUaHxbHHbErfqmYfVVMh9h2TgKcZvYw13940WzdJv0cS2KuK77XBDGBvyMtNikHbfwlaasrGdSkKAZZrEdrP
%SA002gbGGRgQ0GQMCYNi4HIdcbTbCFWcJDnCH7UfhSwwjZTammusHl9juHaAT5pxPeNVdkwv9OqH44OTmv5XeiD1uaSxTNH2u8i
%SA002P0av0XqspIeqUWja5CVLjvismTRhTLOPOmTJyK3FPyeh77evhjFZxmANrKrdXpoML6xTMkK8emlwoN9vYumaBvqRLsg8zs
%SA002H80ZXXnnhZ6cViaSBly3G4xhptIpGKWYjyXThW7R1ERUrmBjxBq7mpKX5hno4LdLitUvMUjOlSFJYy507eyyakjnKtzvU7
MAT1    220     %%              %%      %%      %%  
%SA002CJeM8FK1xQacReDR8E9G5w8BpP1vdbQAEAxSP4fjRVsR6vapexJOzhxqumnfUK6CtDJdkfDRig4EgHO88eVh0fdBk2uunT

Encryption keys and encrypted lines could be placed in include files. GZIP format is also supported.
Entries with encrypted data will not be printed by ECHO and ECHOON commands.
Error/Warning messages related to material/property is protected by replacing real numbers with *****.
Parameter (size) optimization using encrypted material/property is not supported.

Supported Entries

The following entries are currently supported for encryption for Method 1:

Properties:
PBAR, PBARL, PBEAM, PBEAML, PBUSH, PCOMP, PDAMP, PELAS, PDUM1, PGAP, PHFSHL, PROD, PSHEAR, PSHELL, PSOLID, PVISC, PWELD, PMASS, PCOMPG, PTUBE, PAABSF, PACABS, PACBAR, PCOMPP, PFAT, PCONT, PAXI, PSEAM, PWELD, PLY, PBUSHT, PELAST, PGASK, PGAPHT, PCONTHT, PLSOLID, PCOMPLS, PJOINTG, PCOHE, PPLANE
Materials:
MAT1, MAT2, MAT4, MAT5, MAT8, MAT9, MAT10, MATHF, MATT1, MATT2, MATT4, MATT5, MATT8, MATT9, MDUM1, MATFAT, MATEP, MATTEP, MATF, MATG, MATTG, MATHE, MATTHE, MATHP, BLKHDF, MATTORT, MATS1, MATTVE, MATVE, MATVORT, MATVP, MAT3, MATT3, MATHED, MGASK, MCOHE, MCOHED, DMGINI, DMGEVO
Tables
TABLES1, TABLEST, TABLEG, TABLEMD, TABLEM1, TABLEM2, TABLEM3, TABLEM4

Method 2: Encrypt an Entire Include File

The entire include file can be encrypted using Method 2. This allows a simplified and more versatile approach to encrypt data for an OptiStruct run. You can place all the data which should be encrypted (like properties and materials, along with the associated table entries) into a separate include file and use this method to encrypt it. The encrypted file can then be included in the OptiStruct model by replacing the existing include file with the encrypted include file. OptiStruct automatically reads the data using the included encryption key.

Encryption Process

The encryption tool is included in the following locations in the Solvers installation.

Windows:
$ALTAIR_HOME\hwsolvers\optistruct\bin\win64\os_encrypt_v2_win.exe
Linux:
$ALTAIR_HOME/hwsolvers/optistruct/bin/linux64/os_encrypt_v2_linux

For the second method, there are two main differences when compared to the first method:

An entire include file can be encrypted when using the second method (instead of only the partial lines or fields).
The encryption key ID (5 digit alphanumeric key ID) should be specified when running the encryption tool, as shown below.

On Windows, the os_encrypt_v2_win.exe encryption tool can be used to encrypt include files using the following example command (where SE123 is an example encryption key ID):

os_encrypt_v2_win.exe SE123 original_include.fem encrypted_include.fem

On Linux, the os_encrypt_v2_linux encryption tool can be used to encrypt include files using the following example command (where SE123 is an example encryption key ID):

os_encrypt_v2_linux SE123 original_include.fem encrypted_include.fem

After the encryption tool runs, the file encrypted_include.fem, contains both the encryption key and the encrypted lines for all the lines in the original include file.

/ENCRYPT/SE123
1sV2x7KNST5811S9IZuC6ZN6PEF2ODtVJSUMQmCGH9tfDynXLK7G274Rhu3OJ7qQWVNGJHYDJlLV3P97viS8Fw4MBp5MQA9Y1H3V
%SE123MGoRMaLooUWUaHxbHHbKlyvxwZodu52CEbJoOZGd6PbIUfDnbHr5L3aqkRe3QHpEaA1qQcMYhxXUkoWJtJWEefLo3qUbRa
%SE123gbGGRgQ0GQMCYNi4HIdgrvmMWEyo1nt0uqWPSAV2x5M9QnnJxLtDEPwD9AiZlhLpNPCr9J96iyZY8XhfCeI4tCQz7JNbZk
%SE123P0av0XqspIeqUWja5CVPzNt23BnCHL58B8K1yYcYnaQ4l0ZxtvPsubw7vfcne9eYyZEB7DCAIMri1pJaoBtaJUEP7ZP9v0
%SE123H80ZXXnnhZ6cViaSBly9AN2sDnbxoiP3v6AxTWSWBczdHRsXv9mCVQs3voKkxRFJ78XPtjNCBo7rXC1R9hrkU5pVazXVNJ
%SE123CJeM8FK1xQacReDR8E9CrfcsgnpR9XEocQTDCQHWpyJ14PScAKVTzXv8a7NcuXk8hQDSoX0XELsNTa8EI5fPm7ctY8S3sziKC2I3czrRgT6NH18PAF9AItk99fOsQfC4hRbqDTKEMWzLwTR6CW6Ec0TWnaYLM2ZC0zYG6cBI0W8GMkG9dWzxrh1Kiti0
%SE123QuJ6c1TZXFVS0JfXlAIQg9qbR3UAh0Xg9PYvqDI86zowGCTobFA31fgpMVpOeGyQzb8wU6smrb4i2kxPF6Ru3pYNblta25ZVnXIRtwm4H6cmU3JdV6BnQ1Gwobx2DyuzeZxXlCe3BjTmIS1JveRbAmaUwKnazwQyPzBPeNyGC3WpWPvCxnBmHkaIt66c
%SE123cI82yEWIPPRRxKzQjAeUWHPgi1KO5KqwQ02NI1IWJ8Id0foJ2fctBdy741GzxQcC2DzjGpcqoWzzVbd1DHfrsoTHSioOorNc6MOuc52bLayrZgCYpu61TAsHN4x6lst3L9SMOwhv9Ad5rYBxvjbOqNVDmTleWCpdbFvVpdr2t4LllT5pJIw4damZF5yP
%SE123aGGpNgiKjR2qpEOfutncIk50hdZWg464SRiEskzB6iYLub4bvxmxeQaSYTgXIAoaSs3OFjtBc07f9DNY9fFTom2FISxmN9RefGc67DgU3XwcbD3ZJyCg2xrlzK6xZeQcR6QouUowObZ9Z9UD9icwFnPBm2ELPaLne0dBG6rtlQlDmOEA9GYZqkuSAXHj
%SE123ZAQQR4F5HMQ5o5AHK0HRLOueWYeaEScuZ4LzXFESv9RciABdLcLiWKONxryzLHJcFDI1CcAZOh0d64OApjqpibFhjk1STMegJXILbcdHWibXXNnF7BRZCnwKxFo8vfMUTss4NzxMUwONk7vpQukEHVvuXRuh0fpEshViiUPBjCkERKq1U0F3nshAoLpx
%SE123eJHHBxvywZCd0rYTYVXWZTqK5nmNEEwQrkDCLLTp97Gg679SepaFU14YONdViOJIoRjExZtghE2vTalOnaNFntJJXKzcrF59LS77bcjZqsOHDN2CUcLV3TOmPneIFmD10ebAuzzJGUwvO3BFdrNr9K7XdZxZeJTyu311lD89eUTQfTolEk5BFU6JdAty
%SE1239ggGT6OlDAX6X7LQ1xU1Rk6smxjb3OZaHyMdNKjH0xNwpdwqN1Rjj1A6tN0HTRVxGA3t5EoOMMcSVzZBso4jYF0TEHjJ1rGnSjabVtVaKBQTvfcZ5nARG9YqkumuAjMs9NhrmVcDdLhxCsUrHhvhZ7V6qtYdClCTQ3KMISfG8ZjKglZ0NAHOwU8XZOh9
%SE123KKIh3Oxf6UPb6b5i90jCGByKWGwhTgMw7YEro0wTo52XGdooz8sN7a0z1gxqT1NObObJ0im6MUns6EQTkynM45ig0XjbRKRkluR7KD0ue3cDIBlFLyIsscXesXjBJ4RK7UUu0g6s9NY8sso3fpQijxbN4QGCHfQCTQZnT0jT1i3bGWB8KR3UMmclAVx5

Note: The encryption key ID for this example is the keyword SA123 following /ENCRYPT/.

Following this encryption key ID, the first five lines correspond to the encryption key to be used by OptiStruct to decrypt the data. The remaining lines (in this case, there are 8 lines after the encryption key), correspond to the encrypted form of all the lines that were initially in the original_include.fem file.

The encrypted include file can now replace the original include file in the base model.

Supported Entries

The following entries are currently supported for encryption using the second method:

Properties:
PBAR, PBARL, PBEAM, PBEAML, PBUSH, PCOMP, PDAMP, PELAS, PDUM1, PGAP, PHFSHL, PROD, PSHEAR, PSHELL, PSOLID, PVISC, PWELD, PMASS, PCOMPG, PTUBE, PAABSF, PACABS, PACBAR, PCOMPP, PFAT, PCONT, PAXI, PSEAM, PWELD, PLY, PBUSHT, PELAST, PGASK, PGAPHT, PCONTHT, PLSOLID, PCOMPLS, PJOINTG, PCOHE, PPLANE
Materials:
MAT1, MAT2, MAT4, MAT5, MAT8, MAT9, MAT10, MATHF, MATT1, MATT2, MATT4, MATT5, MATT8, MATT9, MDUM1, MATFAT, MATEP, MATTEP, MATF, MATG, MATTG, MATHE, MATTHE, MATHP, BLKHDF, MATTORT, MATS1, MATTVE, MATVE, MATVORT, MATVP, MAT3, MATT3, MATHED, MGASK, MCOHE, MCOHED, DMGINI, DMGEVO
Tables
TABLES1, TABLEST, TABLEG, TABLEMD, TABLEM1, TABLEM2, TABLEM3, TABLEM4