Search results
Results From The WOW.Com Content Network
Length extension attack. In cryptography and computer security, a length extension attack is a type of attack where an attacker can use Hash (message1) and the length of message1 to calculate Hash (message1 ‖ message2) for an attacker-controlled message2, without needing to know the content of message1. This is problematic when the hash is ...
A copy of the code book was obtained in a "black bag" operation on the luggage of a Japanese naval attaché in 1923; after three years of work Agnes Driscoll was able to break the additive portion of the code. [2] [3] [4] Knowledge of the Red Book code helped crack the similarly constructed Blue Book code. [1]
A downgrade attack, also called a bidding-down attack, [1] or version rollback attack, is a form of cryptographic attack on a computer system or communications protocol that makes it abandon a high-quality mode of operation (e.g. an encrypted connection) in favor of an older, lower-quality mode of operation (e.g. cleartext) that is typically provided for backward compatibility with older ...
Python 3.0 broke backward compatibility, and much Python 2 code does not run unmodified on Python 3. [34] Python's dynamic typing combined with the plans to change the semantics of certain methods of dictionaries, for example, made perfect mechanical translation from Python 2.x to Python 3.0 very difficult. A tool called "2to3" does the parts ...
Ciphertext-only attack. In cryptography, a ciphertext-only attack (COA) or known ciphertext attack is an attack model for cryptanalysis where the attacker is assumed to have access only to a set of ciphertexts. While the attacker has no channel providing access to the plaintext prior to encryption, in all practical ciphertext-only attacks, the ...
In cryptography, a Caesar cipher, also known as Caesar's cipher, the shift cipher, Caesar's code, or Caesar shift, is one of the simplest and most widely known encryption techniques. It is a type of substitution cipher in which each letter in the plaintext is replaced by a letter some fixed number of positions down the alphabet .
Cryptography, or cryptology (from Ancient Greek: κρυπτός, romanized:kryptós "hidden, secret"; and γράφειν graphein, "to write", or -λογία -logia, "study", respectively [ 1 ]), is the practice and study of techniques for secure communication in the presence of adversarial behavior. [ 2 ]
World War II cryptography. Cryptography was used extensively during World War II because of the importance of radio communication and the ease of radio interception. The nations involved fielded a plethora of code and cipher systems, many of the latter using rotor machines. As a result, the theoretical and practical aspects of cryptanalysis, or ...