Moxa W406-T-CE [71/74] Binencryptor yourprogram abigkey

7. Software Lock

“Software Lock” is an innovative technology developed by Moxa’s engineers. It can be adopted by a system

integrator or developer to protect applications from being copied. Usually, an application is compiled into a

binary format bound to the embedded computer and the operating system (OS) that the application runs on.

The application can be installed on other computers that use the same hardware and the same operating

system, which means that the application is easily copied.

Moxa’s engineers used data encryption to develop this protective mechanism for your applications. The binary

file associated with each of your applications must undergo an additional encryption process after you have

developed it. The process requires you to install an encryption key on the target computer.

1. Choose an encryption key (e.g., ”ABigKey”) and install it in the target computer with a pre- utility program,

‘setkey’.

#setkey ABigKey

Note: set an empty string to clear the encryption key in the target computer:

#setkey ““

2. Develop and compile your program in the development PC.

In the development PC, run the utility program ‘binencryptor’ to encrypt your program with an encryption

key.

#binencryptor yourProgram ABigKey

3. Upload the encrypted program file to the target computer by FTP or NFS and test the program.

The encryption key is a computer-wise key. That is, a computer has only one key installed. Running the

program ‘setkey’ multiple times causes the key to be over-ridden.

To test the effectiveness of this software protection mechanism, prepare a target computer that has not

installed an encryption key, or install a key different from that used to encrypt your program. In any case, the

encrypted program will fail immediately.

This mechanism also allows a computer with an encryption key to bypass programs that are not encrypted,

allowing you to develop your programs and test them cleanly on the target computer during the development

phase.

NOTE You may error messages in the following circumstances:

1. When you try to run an encrypted program on an embedded computer that does not have the

encryption

key installed.

Error =>

Inconsistency detected by ld.so: dynamic-link.h: 62: elf_get_dynamic_info:

Assertion `! "bad dynamic tag"' failed!

2. When you try to run an encrypted program on an embedded computer that has a different encryption

key installed.

Error =>

Segmentation fault