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PLC encryption way: through programs the software (definite orders) the same program file to read in together the password in PLC. When uses to program the software connects PLC, prompts the input password, then PLC returns to the actual password, realizes the password comparison in the programming software interior. This encryption in reads in PLC the password useless process any encryption computation. Compared with easy to explain! through programs the software to read in together the password same program file in PLC. Reads in PLC the password (scrambled text) to undergo certain encryption computation in the programming software interior (is mostly simple encryption algorithm). When uses to program the software connects PLC, prompts the input password, then the PLC returns scrambled text password, realizes the scrambled text comparison in the programming software interior. This encryption, explains has certain difficulty! Needs to track the analysis programming procedure, discovers the encryption algorithm. through programs the software to read in together the password definite orders same program file in PLC, carries on the encryption by PLC to the password definite orders to calculate the scrambled text to save in PLC. When uses to program the software connects PLC, prompts the input password, PLC does not use the returns scrambled text, realizes the scrambled text comparison in the PLC interior. This encryption way is not easy to realize, needs the PLC hardware and the PLC operating system support. This encryption way is most difficult to explain. decipher: the direct surveillance communication mouth, discovers the definite orders password. the surveillance communication mouth, the track programming software, discovers the password definite orders and the scrambled text relations (algorithm). present does not have the very effective method. each kind explains needs certain skill and the experience, is related the software, the genuine master disdains in this. How writes this article the goal is not to teach everybody to explain, is only cannot get used to seeing the human who certain specialized charges explain the PLC password, reminds the PLC factory to enhance the password the security intensity. |
