Nikos Papanikolopoulos and his colleagues have tested the ability of a series
of robotic “scouts” to gather information. They envisage a group of scouts being
lobbed by a grenade launcher into a building that is too dangerous for police
officers, to explore and send back information via a radio link.

Each robot is roughly the size and shape of a roll of toilet paper, with a
diameter of 4 centimetres. It moves around by rolling and hopping and stays in
touch with other scouts by radio. “The jumping mechanism, along with the
software that makes it jump, is the largest accomplishment,” says
Papanikolopoulos. “Hopping is done by a spring-loaded mechanism that winches in
a leg. Then, suddenly, it is released.”

The impact of the leg hitting the floor causes the robot to jump, “like
kicking a leg”. It can also climb stairs and hurdle small barriers. Two
independent wheels at either end of the cylinder help the robot to roll into
position.

Each scout has a tiny sensor. One has a video camera that pops out of its
body, panning and tilting to capture images of the surrounding area. Other
scouts have small vibration sensors and microphones.

A number of scouts would be deployed at once and controlled from a mobile
“home base”. The 50-kilogram base is in turn operated remotely and acts as a
radio repeater, allowing a greater distance to be maintained between the scouts
and the people digesting the images. The researchers hope that the people will
be more than 400 metres away from the front line.

The concept of multiple robots working together is known as distributed
robotics, explains Paul Schenker, supervisor of the Mechanics and Robotics
Technology Group at NASA’s Jet Propulsion Laboratory near Pasadena, California.
“A number of groups are working on distributed robotics,” he says. The idea is
that multiple robots can provide diverse information about what is going on
inside a building, for example by beaming back video pictures of an object from
different angles.

Papanikolopoulos’s research is being financed by the US military and is
scheduled to be finished by 2002. So far his team has successfully tested the
robot’s locomotion system and the video camera’s ability to pan and tilt.

The main application for the robots will be urban warfare or police rescue
operations. But they could also be useful for civilian intelligence-gathering.
“CNN would love something like this,” says Papanikolopoulos.

Random numbers are in demand as keys for encrypting data. But obtaining a
truly random number is difficult. People are lousy at coming up with them and
computers are worse, although programs are available that generate pseudo-random
numbers. The heat gradient inside lava lamps creates turbulence, however, which
makes the behaviour of the blobs chaotic.

Bob Mende, Landon Noll, and Sanjeev Sisodiya at computer manufacturer Silicon
Graphics used this unpredictability to create genuinely random 128-byte numbers.
Random numbers of this length are used for “strong encryption” schemes. The
researchers call their system Lavarand.

A digital camera snaps a picture of six lava lamps every few minutes,
capturing the random movements of the blobs. It stores each picture as hundreds
of thousands of bytes, but these images are still not sufficiently unpredictable
for the cryptographers. Less than 1 per cent of this information is extracted to
use as the starting point, or seed, for a pseudo-random number generator.

To quote the developers: “A digital camera takes a picture of some Lava Lite
lamps, the digital output of that image is fed into various number mungers and
kablam! you have a bona fide random number.”

Detailed explanations of the Lavar and system are available on the Silicon
Graphics Web site at http://lavarand.sgi.com/.

Lavarand also has political significance. The US government limits the export
of strong encryption technology, under its munitions regulations
(This Week, 6 September, p 27).
But all the algorithms used in Lavarand are already published
and all the hardware is commercially available. So the US government cannot stop
foreign users from duplicating the Lavarand system, and international Web
users can retrieve random numbers as necessary from the server, without
violating the export laws.