a system adapted to provide communication security between computerized devices in , for example , an ad hoc or temporary networked environment . in one embodiment , the network comprises an untrusted network , and the system includes network security apparatus adapted to create security associations between devices on the network , including mutual authentication . traffic between the associated devices may be encrypted for e . g ., data confidentiality and integrity protection . in one variant , the network security apparatus comprises a software entity disposed at least partly within the software stack of the devices . the associated devices may be for example fixed or portable , and may be untrusted .