How is the chip decrypted? What steps are needed and why are some chips so costly to decrypt?

As we all know, in the chip decryption industry, the most correct decryption method is to take the method of hardware decryption, that is, to dissolve the chip with a specific solution, so that the chip is exposed, in the operation of this step, it is also necessary to have some skills. Of course, when operating this step, sometimes, the chip may be dissolved badly, that is, the line is dissolved and broken, so the chip will not be used at all. Of course, if the customer has only one master chip, then you can take it to the binding factory to re-bind, but then, it will incur certain costs, time is also greatly lengthened, generally binding once a week, if the binding test does not pass, then you have to take it again to bind, if such a situation, the technical staff will open a new chip, in order to strive for the shortest possible If such a case, the technician will open another chip again and try to extract the program in the shortest possible time. When the chip is exposed, then we have to use high magnification microscope and FIB (Focused Ion Beam device), with these two devices, find the encrypted position of the chip, change the encrypted chip to a state without encryption by changing its wiring, and then use the programmer to read out the internal program of the chip.

　　Chip processing process

　　1. Chip open cover Open the cover by chemical method or special package type to open the cover and process the gold line to take out the die.
　　2. Layer removal Remove layers by etching, including removing the protective layer polyimide, oxide layer, passivation layer, metal layer, etc.
　　3. Chip staining By staining for easy identification, mainly metal layer brightening, different types of trap area staining, ROM code point staining.
　　4. Chip photography The chip is photographed by SEM.
　　5. Image stitching Stitching the photographed area images (software stitching, manual stitching after photo development).
6.Circuit analysis Capable of extracting digital and analog circuits from chips and organizing them into easy-to-understand hierarchical circuit diagrams, which are released to customers in the form of written reports and electronic data.