Special functions of a CPU 41x-H
6.2 Encrypting blocks
S7-400H
System Manual, 03/2012, A5E00267695-11
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6.2
Encrypting blocks
S7-Block Privacy
The STEP 7 add-on package S7-Block Privacy can be used to encrypt and decrypt functions
and function blocks.
Observe the following information when using S7-Block Privacy:
●
S7-Block Privacy is operated by means of shortcut menus. To view a specific menu help,
press the "F1" function key.
●
You can no longer edit encrypted blocks in STEP 7. Moreover, testing and
commissioning functions such as "Monitor blocks" or breakpoints are no longer available.
Only the interfaces of the encrypted block remain visible.
●
To decrypt blocks, you always need the correct key and the corresponding decompilation
information included in your package. Make sure that the key is always kept in a safe
place.
●
The loading of encrypted blocks is only supported on CPUs as of V6.0.
●
If your project contains sources, you can use these to restore the encrypted blocks by
means of compilation. The S7-Block Privacy sources can be removed from the project.
General procedure
To encrypt the blocks, follow these steps:
1.
In STEP 7, right-click the block container and select "Block protection...".
If you have already selected a specific block, the shortcut menu no longer contains the
"Block protection..." command.
2.
The S7-Block Privacy application is started.
3.
Select the block; multiple selection is supported.
4.
Right-click the block to encrypt and select "Encrypt block...". The "Block encryption"
dialog opens.
5.
Select whether to include decompilation information in the encryption.
Note
If you clear the check box it will no longer be possible to decompile the block!
6.
Enter a key string consisting of at least 12 characters in both fields. Make sure to keep
the key in a secure place. Click "OK" to start encryption.
