Dark_Alex has released yet another breakthrough in the quest of PSP firmware supremacy! He has just released his 2.7X PRXDecrypter application, which does exactly what it sounds like! It can decrypt PSP firmwares that previously couldn't be decrypted such as 2.7. Dark_Alex has only tested it on 2.71m, but the test came out successful so you can bet on it working for firmwares 2.6 and 2.70.

As with...well all of Dark_Alex's programs 2 PSPs are needed, a 1.5 PSP and a PSP running firmware 2.6. Here's the instructions on how to use it:

1.50 part

1. Copy __SCE__psar_dump2 and %__SCE__psar_dump2 to /PSP/GAME/ in the memory stick.
2. Get the DATA.PSAR of the EBOOT.PBP of the update you want to decrypt (2.71 for example) and put it in the root of your memory stick
3. Start the program.

This is simply a psardump (PSpPet) mod that will dump the firmware ENCRYPTED to /F0 and with the correct paths.

2.60 part

1. Be sure you have the F0 folder with the ENCRYPTED dump obtained in the 1.50 part.
2. Copy prxdecrypt27X to /PSP/GAME/ and start the program with the eLoader.
3. The memory stick will flash for some time. When it finishes to flash, resstart the PSP.

You'll now have the decrypted firmware in a new created folder: /FD

So, what does this mean for homebrew? Well, it could lead to an exploit being found in firmware 2.7 if there is one present. I am in no way saying that there is one or this will lead to homebrew on 2.7 so please do not jump to conclusions. It could also lead to 1.5 users being able to launch firmwares 2.6 and 2.7/2.71 on DevHook; so stay tuned to PSPupdates!