TEMPEST and the Bank of England

Since the major British banks first purchased computers in the 1960s, they have been concerned with the security challenges that these machines presented. One of the most potent risks was TEMPEST, the discovery that computers emitted radiation which could reveal the content of information processed by them, even if it had been encrypted. Archival material recently uncovered within the Bank of England’s archives from the mid-late 1970s is presented here to provide a first look at how the Bank evaluated the credibility of the threat posed by TEMPEST and how it sought to manage this new risk.