What is Tempora?

Tempora is the UK's answer to the NSA's PRISM — but arguably more invasive. While PRISM collects data from companies, Tempora taps the physical cables that carry the internet itself.

How It Works

• GCHQ (Government Communications Headquarters) places intercepts on over 200 fiber optic cables landing in the UK
• The UK is a major hub for transatlantic cables connecting Europe and North America
• Tempora captures both content and metadata of communications
• Data is stored for 3 days (content) and 30 days (metadata) in a rolling buffer
• 300 GCHQ analysts and 250 NSA analysts have access to search the data

Scale

At the time of Snowden's revelations:

• Tempora was processing 21 petabytes of data per day
• 46 fiber optic cables were being actively tapped
• Capacity was planned to grow to 200+ cables

Legal Basis

GCHQ operates under the Regulation of Investigatory Powers Act (RIPA) and later the Investigatory Powers Act 2016 (nicknamed the "Snoopers' Charter"). The legal framework:

• Allows bulk collection of "external" communications (anything with one end outside the UK)
• Since most internet traffic is routed internationally, this captures domestic communications too
• Oversight is through secret warrants approved by the Foreign Secretary (not a judge)

Five Eyes Sharing

Tempora data is shared with the Five Eyes alliance (US, UK, Canada, Australia, New Zealand). This creates a surveillance loophole — the NSA can access British-collected data on American citizens, and vice versa, sidestepping domestic legal protections.

Impact

Tempora demonstrated that geography matters for privacy. The UK's position as a fiber optic cable hub gives GCHQ access to a disproportionate share of global internet traffic — making it one of the most powerful surveillance operations in the world.