Method and apparatus for symmetrical key generation secure in a personal safety device with limited trusted relationships

摘要

A data processing method and system for generating a unique symmetric key inside a PSD having limited trust relationships between PSD manufacturer (605), PSD issuer (610), subsequent service providers (615) and a trusted third party (625) where a new composite key is generated (606) using a current composite key and a new symmetric key as input into a composite key generating algorithm.