this is a basic overview of how the DRM Scheme for PlayStation Mobile actually works
as well as advice for how to handle a device with PSM games on it, to avoid loosing them

The important thing: Every PlayStation Mobile game is Encrypted and can only be decrypted if someone owns the game.

it consists of two parts; an activation record, and license file.
activation was a one-time check in with SCE servers; where you would download an activation record "act.dat" the activation record is a per-account key,
that is encrypted with a key derived from your Console ID (on android; it is IMEI/model/vendor/android id, and psm.apk user id,)
a license file would be downloaded every time you downloaded a game from the PS Store; which contains a unique per-game key; however this per-game key, is itself encrypted with the per-account key in the activation record.

This is the reason we cannot just crack every game
basically, despite having every game package that was ever uploaded to SCE servers, we do not have the game-key for each one.
the only way we can get them, is if someone still has the game installed and working on their console/android tablet.

this is not helped by the fact that the licensing process is very fragile, here are some things that would completely break it:
and that the servers that would generate activation records, and/or liecense files are long gone,

The following would make you loose your activation record: (and therefore, every game you own-)

• Factory Resetting your device
• Linking a new PSN account
• "Clear Data" on the PSM app
• Uninstalling the PSM app
• Loosing/otherwise your device breaking
• Flash memory in the device failing
• Clicking "Deactivate" in the settings.

The following would make you loose a given license file:

• Uninstalling a game
• Formatting your memory card/SD Card
• Memory card failing

Keep in mind, that a regular CMA Backup, or copying the files off your SD-Card is not sufficient,
games backed up this way, will ONLY WORK on a device with a valid Activation Record
they will stop working the second you try put them onto another device, or onto another phone or whatever-

Backing up PSM Activation Record

if you want to make a backup of your activation record, the only way is with a modded device, either Henkaku on Vita, (on android; Rooting your phone.)
it can be found on tm0:/psmdrm/act.dat on vita, and /data/data/com.playstation.psstore/files on android.
Keep in mind that these are still paired to your specific device and wont work anywhere else
On android it wont work even if you restore this, because your android id is reset every time you reset your phone, and your psm user id, is reset every time you install PSM.apk. (you can find these using android_id)

False alarms

• in some conditions the vita will check online for some recovation list; can easily bypass this by setting the registry key /CONFIG/PSM/revocation_check_req to 0; license data is intact,
• If the vita saw an update for a game back when the servers were online, but you never installed it; it will always ask you to install that update, and it will always fail; license data is intact,
• Games obtained as a "trial" or "promotion", "demo", etc contain the game key, still; can be easily bypassed with NoPsmDrm; license data is intact,
• Android will fail to launch a game if the content_id is missing from the library cache; license data is intact,
• Android version also won't load if internt is enabled on your phone, this is it checking for updates, can be skipped by just disabling WiFi; license data is intact,