Cryptography Reference
In-Depth Information
CONCLUSION
In the computer age, data security is an issue that
has moved far beyond the narrow circles of military
defense and diplomacy to include the innumerable trans-
actions of everyday life. Data residing on a computer
anywhere is under threat of being stolen, destroyed, or
modified maliciously. This is true whenever the com-
puter is accessible to multiple users but is particularly
significant when the computer is accessible over a net-
work such as the Internet. The first line of defense is to
allow access to a computer only to authorized, trusted
users and to authenticate those users by a password or
similar mechanism. But clever programmers have learned
how to evade such mechanisms. The need to protect sen-
sitive data (for personal as well as national security) has
led to extensive research in cryptography and the devel-
opment of encryption standards for providing a high
level of confidence that the data are safe from decoding
by even the most powerful computer attacks. Computer
theft, however, is not just the theft of information from
a computer; it is also theft by use of a computer, typically
by modifying data. If a bank's records are not adequately
secure, for example, someone could set up a false account
and transfer money into it from valid accounts for later
withdrawal. Such violations of security harm the entire
public, and at the same time advances in cryptographic
systems benefit the entire public—including the vast
majority of people who never suspect that these systems
underlie the keystrokes and mouse clicks that complete
their purchases, pay their bills, and send their messages.
