Let us first explain what is called MCU software soft encryption:

when the microcontroller produces, due to the production process and other reasons, each chip has a difference, use RC to balance this difference. The soft-encryption of the MCU program (or the soft-encryption of the MCU microcomputer) means that the MCU program writes the RC use for encryption and the RC value of the chip verifies in the program; the developer reads the chip with software before programming each chip. The RC value (for example, the RC value of the read A chip is 2C) write into the corresponding program segment. When the IC is programmed, it writes into the A chip according to the RC value (2C), and the chip can use, but If this program corresponds to an IC with an RC value of 2D, the B chip will not work correctly in the system. Suppose the program with only the RC value can write an IC with an RC value (the probability of 2/257, but depends explicitly on the manufacturer’s RC definition). In that case, you don’t know how to change it, so the program does not affect you. So many people can’t use it if they decrypt it. If you need to use it, you need to modify the MCU soft encryption program.