PLC encryption and decryption - Solutions - Huaqiang Electronic Network

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The way plc is encrypted:
The password (plain text) is written to the PLC together with the program file by the programming software. When connecting to the PLC with the programming software, the user is prompted to enter the password, and then the PLC returns the actual password, and the password is compared internally in the programming software. This encryption method does not use any encryption calculations in the password written to the PLC. More easy to crack!
The password is written to the PLC together with the program file by the programming software. The password (cryptotext) written to the PLC is subjected to certain encryption calculations within the programming software (mostly simple encryption algorithms). When connecting to the PLC with the programming software, the user is prompted to enter the password, and then the PLC returns the ciphertext password, and the ciphertext comparison is implemented inside the programming software. This encryption method has a certain difficulty in cracking! Need to trace the analysis programming program to find the encryption algorithm.
The password plaintext is written into the PLC together with the program file by the programming software, and the password is encrypted by the PLC to calculate the ciphertext stored in the PLC. When connecting to the PLC with the programming software, the user is prompted to enter the password, and the PLC does not need to return the ciphertext to compare the ciphertext inside the PLC. This encryption method is also difficult to implement and requires PLC hardware and PLC operating system support. This type of encryption is the most difficult to crack.
PLC decryption method:
Monitor the communication port directly to find the clear text password.
Monitor the communication port, track the programming software, and find out the relationship between the plaintext and ciphertext of the password (algorithm).
There is currently no very effective method.
Various cracks require certain skills and experience, and related software. Real masters disdain this. The purpose of writing this article is not to teach you how to crack, but just can't understand the people who charge the PLC password for some professional fees, remind the PLC manufacturers to improve the confidentiality of the password.