I'm not saying a mod chip is impossible; I'm saying custom firmware is impossible. The PSP will not boot if the bootloader is signed by Sony's private key, and there's no way to get that by "cracking" encryption. It's not stored anywhere on the PSP, and brute-forcing the key would take somewhere around 10,000,000,000,000,000 years. So... It's BS, complete and utter. Closed.