In a pure mathematical attack, (i.e., lacking any other information to help break a cipher) two factors above all count: 1  Computational power available, i.e., the computing power which can be brought to bear on the problem. 2  Key size, i.e., the size of key used to encrypt a message.
OMB's guidance to agencies requires them to report each PII-related breach to DHS's U.S. Computer Emergency Readiness Team (US-CERT) within 1 hour of discovery. However, complete information from most incidents can take days or months to compile; therefore preparing a meaningful report within 1 hour can be infeasible.
Today, CERT focuses on security breach and denial-of-service incidents, providing alerts and incident-handling and avoidance guidelines. CERT also conducts an ongoing public awareness campaign and engages in research aimed at improving security systems.