A passive attack on a cryptosystem is one in which the cryptanalyst cannot interact with any of the parties involved, attempting to break the system solely based upon observed data (i.e. the ciphertext). This can also include known plaintext attacks where both the plaintext and its corresponding ciphertext are known.
While most classical ciphers are vulnerable to this form of attack, most modern ciphers are designed to prevent this type of attack above all others.
Read more about Passive Attack: Attributes, Further Reading
Famous quotes containing the words passive and/or attack:
“We have not passed that subtle line between childhood and adulthood until we move from the passive voice to the active voice—that is, until we have stopped saying “It got lost,” and say, “I lost it.””
—Sydney J. Harris (b. 1917)
“...I believed passionately that Communists were a race of horned men who divided their time equally between the burning of Nancy Drew books and the devising of a plan of nuclear attack that would land the largest and most lethal bomb squarely upon the third-grade class of Thomas Jefferson School in Morristown, New Jersey.”
—Fran Lebowitz (b. 1950)