PSSE

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What is PSSE?

PSSE stands for PlayStation Suite Encrypted. It is an encryption layer that encrypts the PSM game's filesystem.

The encryption layer is comparable to the PS Vita Filesystem in many ways; however, it seemed that there was a bug at Sony, where besides executable files, the first directory level of a PSM app is not encrypted with PSSE, whose directory level is below the root of RO/. Similarly, the PSM SaveData is not encrypted by such layer either.

Data Structure

offset value description
0x00 0x50535345 (ASCII "PSSE") Magic Number / File Header
0x14 CONTENT_ID Contents of /RW/System/content_id
0x40 Signature Generated by PSMSDK 'publisher key'? - Similar to sce_sys/clearsign file of NpDrm-Encrypted apps
0x180 Encrypted Keys Generated by PSMSDK 'app key' and 'app seed'? - Similar to sce_sys/keystone file of NpDrm-Encrypted apps
0x680 Encrypted Data Actual cipher-text for the encrypted file

Decryption

PSSE Can be decrypted using the http://bitbucket.org/SilicaAndPina/FuckPSSE plugin by SilicaAndPina