Cryptography Reference
In-Depth Information
chapter
6
MODERN ELECTRONIC
CRYPTOGRAPHY
With the invention of electromechanical rotor
machines after World War I, the secure size of
ciphers grew accordingly, so that tens or even hundreds
of thousands of characters were feasible. After World War
II, a switch from electromechanical devices to electronic
ones accelerated this trend. To illustrate the progress
that was made in only eight decades, in 1999 the U.S.
government designed and fabricated a single silicon chip
implementation of the Data Encryption Standard (DES)
with a demonstrated throughput of 6.7 billion bits (6.7
gigabits) per second. The Advanced Encryption Standard
(AES), meanwhile, could be implemented in a single sil-
icon chip to handle 10
10
bits per second (10 gigabits per
second) on an Internet backbone circuit. In a few seconds
of operation, trillions of bits of cipher could be processed,
compared with the tens of bits per second possible with
the first mechanized cipher machines. By the beginning
of the 21st century the volume of ciphertext that had to
be dealt with on a single communications channel had
increased nearly a billionfold, and it continues to increase
at an ever-expanding rate.
The last two decades of the 20th century marked the
most radical change of all in the history of cryptology—its
dramatic extension to the information age: digital signa-
tures, authentication, shared or distributed capabilities to
exercise cryptologic functions, and so on. It is tempting
