PIC microcontrollers use Code Protection bits to prevent firmware readout. PIC decryption removes protection to recover source code.

PIC Code Protection:
- Config bits set CP (Code Protect) to lock flash.
- Reading protected code returns garbage or 0x00.
- Resetting config bits normally mass-erases the chip.

PIC Decryption Methods:
1. Voltage Glitching: spike Vdd during protect check.
2. Overclocking: force the chip to skip protection logic.
3. UV Erasure: old EPROM parts can be selectively UV-erased.
4. Decapsulation: open package and read flash microscopically.
5. ICSP Glitching: fault injection via ICSP pins.

PIC decryption is common for:
- Legacy 8-bit product backup
- Repairing obsolete equipment
- Recovering lost source code
- PCB cloning and reverse engineering