The Centre for the Protection of National Infrastructure (CPNI) protects national security by providing protective security advice. Protective security is 'putting in place, or building into design, security measures or protocols such that threats may be deterred, detected, or the consequences of an attack minimised'.
CPNI teams provide advice on physical security, personnel security and cyber security/information assurance. Most importantly, they explain how those components combine together and reinforce each other - and their relationship to the threat”
Website - http://www.cpni.gov.uk/