Simmons say Havana has long relied on short wave radio to send encoded messages using a system that converts letters into numbers.

VOA: standard.2009.06.06

If deployed, it means that a passport, for example, could be quickly scanned using the system and its laser speckles recorded and encoded in a unique serial number or onto a database before being issued.

BBC: NEWS | Technology | Laser spots paper 'fingerprints'

In practice, this system allowed for 100-percent accuracy in sequencing and retrieving the encoded files.

ENGADGET: Scientists encode Shakespeare sonnets, MP3 and more into glitch-free DNA