Monday, May 19, 2014

How to wiretap a country

The latest Snowden leak is that the NSA has been wiretapping all of the nation of The Bahamas -- not just the metadata, but full audio. How much data is that? Here are some numbers:

  • 12.2 kilobits/second = high-quality audio codec used by cellphones
  • 58 minutes = average time American spends on phone per day (proxy for Bahamians)
  • 371,960 = population of The Bahamas

Multiply these numbers together and you get the surprising number of:

1.84 terabytes/day

That's the size of a $90 hard drive worth of data every day, or $33,000 per year worth of storage.

Or, in terms of bandwidth, it's 160-mbps -- a lot slower than the gigabit Ethernet connection on your laptop.

The upshot is this: technologically, the ability to intercept an entire nation is trivial.


Unknown said...

Wait, that's an upshot? ;)

Unknown said...

Only 26% of that 58 minutes is voice, so isn't it 478GB/Day?

George said...

G.729 compressed is 8 Kbps. G.711 is 64 Kbps. It's unlikely you're going to compress further than 8 Kbps even with silent time.