The "sandbox" being referred to is the "Secure Enclave", which apparently is what ARM calls "TrustZone": http://infocenter.arm.com/help/topic/com.arm.doc.prd29-

The "sandbox" being referred to is the "Secure Enclave", which apparently is what ARM calls "TrustZone": http://infocenter.arm.com/help/topic/com.arm.doc.prd29-genc-009492c/PRD29-GENC-009492C_trustzone_security_whitepaper.pdf http://infocenter.arm.com/help/topic/com.arm.doc.prd29-genc-... The data isn't accessible to even the OS. So, in theory at least, jailbreaking doesn't make it any more accessible.