> a specially formatted save file on the memory card, leading to a buffer overflow that gives access to otherwise protected memory > ... Then CTurt used the sy

> a specially formatted save file on the memory card, leading to a buffer overflow that gives access to otherwise protected memory > ... Then CTurt used the system's USB save import feature to get that file onto the target system. > ... one of the few PS2 games released as physical, PS4-compatible discs As the number of such games is limited, it would be trivial to implement a save-file validation parser in the USB save import feature for these games and push it as a mandatory update. For digitally delivered titles, then you can patch the emulator. (EDIT: unless, the save file contains executable code. Seen it before, done as an obfuscation technique. Next point still apllies, though) Also, > had to use an already-hacked PS4 to digitally sign a modified Okage Shadow King save file, letting it work with his PSN ID. For that, change the workflow so that at each SW update you generate a new certificate. Upon releasing a new FW version, revoke all previous certificates.