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| In cryptography, encryption
is the process of transforming information (referred to as plaintext)
to make it unreadable to anyone except those possessing special
knowledge, usually referred to as a key. The result of the process
is encrypted information (in cryptography, referred to as cipher
text). In many contexts, the word encryption
also implicitly refers to the reverse process, decryption (e.g.
“software for encryption”
can typically also perform decryption), to make the encrypted
information readable again (i.e. to make it unencrypted). |
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| Encryption
has long been used by militaries and governments to facilitate
secret communication. Encryption
is now used in protecting information within many kinds of civilian
systems, such as computers, networks (e.g. the Internet e-commerce),
mobile telephones, and bank automatic teller machines. Encryption
is also used in digital rights management to restrict the use
of copyrighted material and in software copy protection to protect
against reverse engineering and software piracy. |
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| Encryption,
by itself, can protect the confidentiality of messages, but
other techniques are still needed to verify the integrity and
authenticity of a message; for example, a message authentication
code (MAC) or digital signatures. Standards and cryptographic
software and hardware to perform encryption
are widely available, but successfully using encryption
to ensure security is a challenging problem. A single slip-up
in system design or execution can allow successful attacks.
Sometimes an adversary can obtain unencrypted information without
directly undoing the encryption
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Source: (www.en.wikipedia.org)
2007
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