Renesas RL78 16-bit MCU uses flash protection. RL78 decryption bypasses it to recover firmware.

RL78 Protection:
- Security ID prevents flash readout.
- On-chip debug interface can be locked.
- Flash programming is password-protected.
- Block erase and read are restricted.

RL78 Decryption Methods:
1. Voltage Glitching: glitch VDD during security check.
2. Clock Glitching: fault flash controller.
3. Decapsulation: read silicon die directly.
4. Side-Channel: power analysis during access.

RL78 is used in automotive, home appliances, and industrial control.