It may not be the cleanest code; however, developers looking to learn by example, here you go… Maxthebest has open-sourced his ProtectMe homebrew app under the GNU General Public License (GPL).

Download it, learn from it, maybe even enhance it — it’s all on you.

Download:
ProtectMe source code
ProtectMe v0.92

- source: maxence-dev

Don’t like to share? Protect your PSP from unauthorized use with MaxTheBest’s Protect Me. An EBOOT / PRX combo adding password authentication before the XMB is loaded.

Protect Me v0.92 improves overall usability and corrects many bugs.

Protect Me v0.92 changes:

• Now when the alarm is played, the PSP volume is automatically set to maximum volume (noisy little trick ^^)
• An option menu has been added (working with a file which is ms0:/seplugins/config.mtb)
• In the option menu you can set to play the alarm sound after 3 wrong passwords or not.
• The Credits have been updated
• The credit, the option, and the set password menus have been modified so you can more easily exit (exit key used to be different in each menu, now it’s the same.)
• Now, when you set the password, a confirmation message is displayed, telling you what password you are trying to set, and asking you if you still want to set it or not.
• Colors have been changed in some menus (No more red, it was too much ‘aggressive’ wasn’t it?)
• Menus have been optimized
• Now splash screen is only displayed at first use, and then it isn’t (so you can access menu faster…)
• The On Screen Keyboard has been modified, it used to be kind of complicated (when you pressed up or down, you never happened to go to the letter you wanted to go to… now you should)
• Many minor bugs have been corrected…

Download: Protect Me v0.92

- source: pspgen

As we near the Homebrew Idol finale, developer MaxTheBest shares his creation — Protect Me. A simple yet effective homebrew app wrapped around a PRX plugin. The PRX is called on-boot prompting the user to enter his/her password before granting access to the XMB. So all that filth you wish to hide from your unsuspecting friends, siblings, etc… It’s safe now — for the most part.

Installation is easy — copy the “Protect-Me” directory to PSP/GAME on your memory stick, and run it. From here the rest is pretty straightforward: install / uninstall the PRX, set or remove your password, and so forth… As per the screenshot:

“Max, you the best.” Now that my unmentionables are safely protected.

Protect Me 0.91 changes:

• Now when the intruder inputs 3 wrong password, an alarm will be played to alert you about the thief.
• Some bugs corrected.

Download: Protect Me v0.91