Cryptography

Cryptography (or cryptology; from Greek κρυπτός kryptós, "hidden, secret"; and γράφειν graphein, "writing", or -λογία -logia, "study", respectively) is the practice and study of techniques for secure communication in the presence of third parties (called adversaries).

Description

More generally, it is about constructing and analyzing protocols that block adversaries.

Cryptography is central to various aspects of information security, including:

• [[Data confidentiality]
• Data integrity
• Data authentication
• Data non-repudiation

Modern cryptography exists at the intersection of the disciplines of mathematics, computer science, and electrical engineering.

Applications of cryptography include ATM cards, computer passwords, and electronic commerce.

Early cryptography

Cryptography prior to the modern age was effectively synonymous with encryption, the conversion of information from a readable state to apparent nonsense. The originator of an encrypted message shared the decoding technique needed to recover the original information only with intended recipients, thereby precluding unwanted persons from doing the same.

Modern cryptography

Since World War I and the advent of the computer, the methods used to carry out cryptology have become increasingly complex and its application more widespread.

Modern cryptography is heavily based on mathematical theory and computer science practice.

Cryptographic algorithms are designed around computational hardness assumptions, making such algorithms hard to break in practice by any adversary.

See also

• Adversary (cryptography)
• Algorithm
• Computer science
• Computer security
• Data confidentiality
• Data integrity
• Data authentication
• Data non-repudiation
• Electrical engineering
• Encryption
• Information security
• Mathematics
• Turing, Alan
• Security

External links

• Cryptography @ Wikipedia