May 31st has come and gone. It was the deadline for registering an account on Playstation Mobile, and many of us are now anxious to know “what’s next” for Yifan Lu.

PSM Hack: the story

Yifan Lu announced a while ago that people should download the PSM dev assistant and install it on their vita. He also recommended people to get a PSM publisher license. That last step turned out to be tricky: with the increase of publisher license requests, Sony could not catch up with the demand and not everybody got approved. Sony started asking for proof that people requesting the license would actually publish a game, and ultimately stopped approving requests altogether, as they had announced.

Now that nobody can join the PSM program, people are wondering if Yifan Lu will finally “reveal” what this is all about. Although he was not always clear on why he suggested everyone to do that, putting the pieces together is not very difficult, and it seems he has a hack in preparation.

I myself do not know all the details, and I didn’t ask. It’s my philosophy that the less people know about something like that while it’s under wrap, the better. If Yifan wanted to give me more details, he would have given them to me.

What will the PSM hack allow us to do?

Yifan Lu initially said that people should get a PSM Publisher license. Such a license is a prerequisite to test your own apps on your own PS Vita. One could imagine that people could share their PSM Source code with each other, and everyone with a publisher key could compile and run “homebrews” this way. A major issue though is that test publisher keys have a limited validity in time. It’s not a stretch to assume that Yifan Lu has found at least a way to bypass this limitation. This would allow people with a Psm publisher license to compile and run their own code, without having to run through Sony’s approval. Homebrews could be exchanged in source code packages between the lucky PSM publisher licensed. That sounds like it would be a very “niche” use case.

Yifan Lu has however stated a few times now that the PSM Publisher key is not necessary. This implies there is a solution to let people without a publisher key run these tests. I’ll let your imagination work here, but you could imagine anything, from a bug in the PSM Dev App to a way of sharing keys between users without Sony knowing.

This would allow everyone to create PSM apps even after the PSM program is over, assuming people don’t update their Vita (a software patch preventing the PSM Dev App from running is always a possibility)

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What sounds odd to me, in that scenario, is the need for a scene Vita SDK (Yifan Lu asked for help on this a few days ago, you can help if you have SDK creation experience and even if you don’t own a Vita). We could, after all, use the PSM SDK as is. In my mind, this points to an additional vulnerability in the PSM engine, which would give us additional access to the Vita. This could, after all, be the awaited release of UVL.

That’s 2 reasons to be excited in my opinion: we could see the rise of PSM specific homebrew, which in itself would be awesome progress for the Vita scene, but also maybe the possibility of deeper access to the Vita internals through a hack in PSM.

When will the PSM hack be released?

I contacted Yifan Lu about his schedule, and we had a quick chat. He said there is no rush at this point, and recommends people to get and install the psm dev app on their Vita. He’s pretty busy this week but we’ll be following up as soon as possible.