Three units were used to measure consumption: hardware

binary digits, words, and hours.

Now, how many

binary digits are needed to encode an analog signal, such as a picture or analog TV signal?

The transmitted

binary digits are decoded at the receiving end.

In the world of computing, however, data is stored as 0s and 1s (known as

binary digits, or bits).

Duobinary coding technique involves a correlation span of two

binary digits ([a.sub.k], [a.sub.k - l]).

Designed and built by Paul Kocher of Cryptography Research in San Francisco and his coworkers, the new code-cracking computer incorporates more than 1,000 integrated-circuit chips specifically configured for checking the strings of 56

binary digits that comprise DES encryption keys.

To measure the approximate entropy of the

binary digits of pi, [square root of 2], [square root of 3], and e, Pincus determined how often each of eight blocks of three consecutive digits--000, 001, 010, 011, 100, 101, 110, and 111--comes up in the first 280,000 digits of the number.

He and his coworkers succeeded in creating a potentially useful, efficient linear code based not on

binary digits (0,1) but on quaternary digits (0,1,2,3).

By designating one lobe as 0 and the other as 1, the researchers can capture the trajectory's wanderings as a sequence of

binary digits.

Each of four bases is given a value of either 0 or 1 to generate a string of

binary digits. Taken in groups of three, these digits are assigned specific directions on the lattice (lower left).

Thus, proof checking can be done electronically when the whole procedure is encoded as strings of

binary digits. This makes it possible to use this concept for password protocols and in cryptological games like tossing a coin by telephone or exchanging secret keys (SN:9/26/81, p.205).