A portable electronic device is operable as a portable certification authority. The portable electronic device stores a pair of keys of a public key infrastructure, issued by a parent certification authority and generates a certificate dependent upon the pair of keys. The private key and corresponding public key certificate are transmitted to a network device of a second agency to allow the device to be authenticated by any node of the network of the first agency that posses anchor information of the parent certification authority. This enables the device of the second agency to be authenticated by a network node of the first agency.