The flexibility and power achieved by using Active Networks come with their own risks - any fault in the active code or the security infrastructure now represents a fault in the network as a whole. Secure containment of active code is necessary in order to ameliorate this risk. The Active Network Fault Response project has developed and implemented innovative approaches to respond to faults in the active code as well as faults in the security infrastructure of an active network. Diverse authentication techniques, which provide fail-over, and compensatory authentication techniques, which provide substitutes, furnish effective responses when some component of the security infrastructure is unavailable. An active code revocation capability provides for secure containment of faulty active code within the active network.