Encyclopedia - Computer Forensics: Encyclopedia Ii - Computer Forensics - Secure The Machine And The Data
Unless completely unavoidable, data should never be analyzed using the same machine it is collected from. Instead, forensically sound cop...   » Read the article

Encyclopedia - Computer Insecurity: Encyclopedia Ii - Computer Insecurity - Security And Systems Design
Most current real-world computer security efforts focus on external threats, and generally treat the computer system itself as a trusted ...   » Read the article

Encyclopedia - Caesar Cipher: Encyclopedia - Caesar Cipher
In cryptography, a Caesar cipher, also known as a Caesar's cipher or the shift cipher, is one of the simplest and most widely-known encry...   » Read the article

Encyclopedia - Colossus Computer: Encyclopedia - Colossus Computer
The Colossus machines were early computing devices used by British codebreakers to read encrypted German messages during World War II. Co...   » Read the article

Encyclopedia - Sigint: Encyclopedia - Sigint
SIGINT stands for SIGnals INTelligence, which is intelligence-gathering by interception of signals, whether by radio interception or othe...   » Read the article

Encyclopedia - Brute Force Attack: Encyclopedia - Brute Force Attack
In cryptanalysis, a brute force attack is a method of defeating a cryptographic scheme by trying a large number of possibilities; for exa...   » Read the article

Encyclopedia - Analysis: Encyclopedia - Analysis
An analysis is a critical evaluation, usually made by breaking a subject (either material or intellectual) down into its constituent part...   » Read the article

Encyclopedia - Computer: Encyclopedia - Computer
A computer is a machine capable of processing data according to a program — a list of instructions. The data to be processed may repres...   » Read the article

Encyclopedia - Computer Forensics: Encyclopedia Ii - Computer Forensics - Understand The Suspects
It is absolutely vital for the forensics team to have a solid understanding of the level of sophistication of the suspect(s). If insuffic...   » Read the article

Encyclopedia - Block Cipher: Encyclopedia - Block Cipher
In cryptography, a block cipher is a symmetric key cipher which operates on fixed-length groups of bits, termed blocks, with an unvarying...   » Read the article

Encyclopedia - Information Theory: Encyclopedia - Information Theory
Information theory is the mathematical theory of data communication and storage, generally considered to have been founded in 1948 by Cla...   » Read the article

Encyclopedia - Crib Cryptanalysis: Encyclopedia - Crib Cryptanalysis
In cryptanalysis, a crib is a sample of known plaintext; the term originated at Bletchley Park, the British codebreaking operation during...   » Read the article

Encyclopedia - Umbrella Term: Encyclopedia - Umbrella Term
An umbrella term is a word that provides a superset or grouping of related concepts. Thus cryptology is an umbrella term that encompasses...   » Read the article

Encyclopedia - Ultra: Encyclopedia - Ultra
Ultra (sometimes capitalised ULTRA) was the name used by the British for intelligence resulting from decryption of German communications ...   » Read the article

Encyclopedia - Data Encryption Standard: Encyclopedia - Data Encryption Standard
The Data Encryption Standard (DES) is a cipher (a method for encrypting information) selected as an official Federal Information Processi...   » Read the article

Encyclopedia - Unicity Distance: Encyclopedia - Unicity Distance
Unicity distance is a term used in cryptography referring to the length of an original ciphertext needed to break the cipher by reducing ...   » Read the article

Encyclopedia - Cryptography: Encyclopedia - Cryptography
Cryptography is the field concerned with linguistic and mathematical techniques for securing information, particularly in communications....   » Read the article

Encyclopedia - Venona Project: Encyclopedia - Venona Project
The VENONA project was a long-running and highly secret collaboration between United States intelligence agencies and the United Kingdom'...   » Read the article

Encyclopedia - Cross-correlation: Encyclopedia - Cross-correlation
In statistics, the term cross-correlation is sometimes used to refer to the covariance cov(X, Y) between two random vectors X and Y,...   » Read the article

Encyclopedia - List Of Cryptographers: Encyclopedia - List Of Cryptographers
Cryptography List of cryptographers - Pre-computer. Charles Babbage, UK, 19th century mathematician who, about the time of the Crimean...   » Read the article

Encyclopedia - Computer Insecurity: Encyclopedia - Computer Insecurity
Many current computer systems have a very poor level of computer security. This computer insecurity article describes the current battlef...   » Read the article

Encyclopedia - Compromise: Encyclopedia - Compromise
A compromise is an agreement (or proposed agreement) to accept a situation in which the parties allow variations from what they originall...   » Read the article

Encyclopedia - Advanced Encryption Standard Process: Encyclopedia - Advanced Encryption Standard Process
The Advanced Encryption Standard (AES), the block cipher ratified as a standard by National Institute of Standards and Technology (NIST),...   » Read the article

Encyclopedia - Computer Forensics: Encyclopedia Ii - Computer Forensics - Electronic Evidence Considerations
Like any other piece of evidence used in a case, the information generated as the result of a computer forensics investigation must follo...   » Read the article

Encyclopedia - Encryption: Encyclopedia - Encryption
In cryptography, encryption is the process of obscuring information to make it unreadable without special knowledge. While encryption has...   » Read the article

Encyclopedia - Strength: Encyclopedia - Strength
Strength may refer to psychological stength Physical strength of organisms' means (especially the muscles of most metazoa) of locomotion...   » Read the article

Encyclopedia - Sigaba: Encyclopedia Ii - Sigaba - History
It was clear to US cryptographers well before WWII that the single-stepping mechanical motion of rotor machines (e.g. the Hebern machine)...   » Read the article

Encyclopedia - Quantum Computer: Encyclopedia Ii - Quantum Computer - The Basis Of Quantum Computing
In quantum mechanics, the state of a physical system (such as an electron or a photon) is described by an element of a mathematical objec...   » Read the article

Encyclopedia - Substitution Cipher: Encyclopedia Ii - Substitution Cipher - Simple Substitution
Substitution over a single letter—simple substitution—can be demonstrated by writing out the alphabet in some order to represent the ...   » Read the article

Encyclopedia - Supercomputer: Encyclopedia Ii - Supercomputer - Design
Supercomputers traditionally gained their speed over conventional computers through the use of innovative designs that allow them to perf...   » Read the article

Encyclopedia - Advanced Encryption Standard Process: Encyclopedia Ii - Advanced Encryption Standard Process - Rounds One And Two
In the nine months that followed, fifteen different designs were created and submitted from several different countries. They were, in al...   » Read the article

Encyclopedia - Battle Of Cape Matapan: Encyclopedia Ii - Battle Of Cape Matapan - Forces
The Allied forces were centred on the Mediterranean fleet, consisting of the aircraft carrier HMS Formidable, the modernised World War I ...   » Read the article

Encyclopedia - Boomerang Attack: Encyclopedia Ii - Boomerang Attack - The Attack
The boomerang attack is based on differential cryptanalysis. In differential cryptanalysis, an attacker exploits how differences in the i...   » Read the article

Encyclopedia - Books On Cryptography: Encyclopedia Ii - Books On Cryptography - Early History
An early example of a book about cryptography was a Roman work, now lost and known only by references. Many of the early works on cryptog...   » Read the article

Encyclopedia - Blowfish Cipher: Encyclopedia Ii - Blowfish Cipher - The Algorithm
Blowfish has a 64-bit block size and a key length of anywhere from 32 bits to 448 bits. It is a 16-round Feistel cipher and uses large ke...   » Read the article

Encyclopedia - Technological Escalation During World War Ii: Encyclopedia Ii - Technological Escalation During World War Ii - Between The Wars
After World War I many innovations in metals and chemicals had created withering firepower that made defenses effective. In France the le...   » Read the article

Encyclopedia - Caesar Cipher: Encyclopedia Ii - Caesar Cipher - History And Usage
The Caesar cipher is named after Julius Caesar, who, according to Suetonius, used it with a shift of three to protect messages of militar...   » Read the article

Encyclopedia - Pretty Good Privacy: Encyclopedia Ii - Pretty Good Privacy - Recent Developments
During all of this turmoil, Zimmermann's team worked on a new version of PGP called PGP 3. This new version was to have considerable secu...   » Read the article

Encyclopedia - Numb3rs: Encyclopedia Ii - Numb3rs - Characters
NUMB3RS - Don Eppes. Don Eppes is one of the two main characters in the show. Don is an FBI Special Agent who recruits his mathematical...   » Read the article

Encyclopedia - Martin Gardner: Encyclopedia Ii - Martin Gardner - Selected Works
Note: Gardner has a number of magic books written "for the trade", which are not listed here. Martin Gardner - Chronology of selected bo...   » Read the article

Encyclopedia - Malbolge: Encyclopedia Ii - Malbolge - Programming In Malbolge
Malbolge was so difficult to understand when it arrived that it took two years for the first Malbolge program to appear. The program was ...   » Read the article

Encyclopedia - Brute Force Attack: Encyclopedia Ii - Brute Force Attack - Symmetric Ciphers
For symmetric-key ciphers, a brute force attack typically means a brute-force search of the key space; that is, testing all possible keys...   » Read the article

Encyclopedia - Block Cipher: Encyclopedia Ii - Block Cipher - Generalities
A block cipher consists of two paired algorithms, one for encryption, E, and another for decryption, E-1. Both algorithms accept two inpu...   » Read the article

Encyclopedia - Ultra: Encyclopedia Ii - Ultra - Use Of Ultra
Usable Ultra information came too late to be of great help during the Battle of Britain. The Allies were seriously concerned to conceal f...   » Read the article

Encyclopedia - Venona Project: Encyclopedia Ii - Venona Project - The Break-in
The Soviet systems in general used a code to convert words and letters into numbers, to which an additive key (from one-time pads) were a...   » Read the article

Encyclopedia - Advanced Encryption Standard Process: Encyclopedia Ii - Advanced Encryption Standard Process - Rounds One And Two
In the nine months that followed, fifteen different designs were created and submitted from several different countries. They were, in al...   » Read the article

Encyclopedia - Conel Hugh O'donel Alexander: Encyclopedia Ii - Conel Hugh O'donel Alexander - Codebreaking At Bletchley Park
In February 1940 Alexander arrived at Bletchley Park, the British codebreaking centre during World War II. He joined Hut 6, the section t...   » Read the article

Encyclopedia - Cryptographically Secure Pseudorandom Number Generator: Encyclopedia Ii - Cryptographically Secure Pseudorandom Number Generator - Designs
For our discussion we can divide the designs of CSPRNGs into three classes: 1) those based on block ciphers, 2) those based upon hard mat...   » Read the article

Encyclopedia - Piling-up Lemma: Encyclopedia Ii - Piling-up Lemma - Theory
The piling-up lemma allows the cryptanalyst to determine the probability that the equality: holds, where the X 's are binary variables...   » Read the article

Encyclopedia - Pretty Good Privacy: Encyclopedia Ii - Pretty Good Privacy - Recent Developments
During all of this turmoil, Zimmermann's team worked on a new version of PGP called PGP 3. This new version was to have considerable secu...   » Read the article

Encyclopedia - Newdes: Encyclopedia Ii - Newdes - The Algorithm
NewDES, unlike DES, has no bit-level permutations, making it easy to implement in software. All operations are performed on whole bytes. ...   » Read the article

Encyclopedia - Marian Rejewski: Encyclopedia Ii - Marian Rejewski - Solution Of The Enigma Wiring
First, Rejewski tackled the problem of finding the wiring of the rotors. To do this, he pioneered the use of pure mathematics in cryptana...   » Read the article

Encyclopedia - Playfair Cipher: Encyclopedia Ii - Playfair Cipher - Using Playfair
The Playfair cipher uses a 5 by 5 table containing a key word or phrase. Memorization of the keyword and 4 simple rules was all that was ...   » Read the article

Encyclopedia - Side Channel Attack: Encyclopedia Ii - Side Channel Attack - Examples
A timing attack watches data movement into and out of the CPU, or memory, on the hardware running the cryptosystem or algorithm. Simply b...   » Read the article

Encyclopedia - Xsl Attack: Encyclopedia Ii - Xsl Attack - Solving Multivariate Quadratic Equations
Solving multivariate quadratic equations (MQ) is an NP-hard problem (in the general case) with several applications in cryptography. The ...   » Read the article

Encyclopedia - Two-square Cipher: Encyclopedia Ii - Two-square Cipher - Algorithm
Encryption using two-square is basically the same as the system used in four-square, except that the plaintext and ciphertext digraphs us...   » Read the article

Encyclopedia - Solitaire Cipher: Encyclopedia Ii - Solitaire Cipher - Algorithm
This algorithm assumes that the user has two or four decks of cards and two jokers. For simplicity's sake, only two decks will be used in...   » Read the article

Encyclopedia - Macguffin Cipher: Encyclopedia Ii - Macguffin Cipher - The Algorithm
Schneier and Blaze based MacGuffin on DES, their main change being that the data block is not split into equal halves in the Feistel netw...   » Read the article

Encyclopedia - Linear Feedback Shift Register: Encyclopedia Ii - Linear Feedback Shift Register - How It Works
The list of the bits positions that affect the next state is called the tap sequence. In the diagram below, the sequence is [16,14,13,11]...   » Read the article

Encyclopedia - Frequency Analysis: Encyclopedia Ii - Frequency Analysis - Frequency Analysis For Simple Substitution Ciphers
In a simple substitution cipher, each letter of the plaintext is replaced with another, and any particular letter in the plaintext will a...   » Read the article

Encyclopedia - Four-square Cipher: Encyclopedia Ii - Four-square Cipher - Algorithm
To encrypt a message, one would Follow these steps: Split the payload message into digraphs. (HELLO WORLD becomes HE LL OW OR LD) Find t...   » Read the article

Encyclopedia - Cryptography In Japan: Encyclopedia Ii - Cryptography In Japan - Japanese Cryptology From The 1500s To 1910s
The cipher system that Uesugi used is basically a simple substitution usually known in English as a Polybius square or “checkerboard.â€...   » Read the article

Encyclopedia - Harvest Computer: Encyclopedia Ii - Harvest Computer - Usage
One purpose of the machine was to search text for key words from a watchlist. From a single foreign cipher system, Harvest was able to sc...   » Read the article

Encyclopedia - Information Forensics: Encyclopedia Ii - Information Forensics - Investigation Concerns
Investigations characteristically seek to identify the perpetrators, uncover the processes that lead to the creation of the system in que...   » Read the article

Encyclopedia - Key Server Cryptographic: Encyclopedia Ii - Key Server Cryptographic - Weaken Security
Uploading a key to a key server reduces the level of security that can be expected from the key. The reduction is minor, but not insignif...   » Read the article

Encyclopedia - James Alfred Ewing: Encyclopedia Ii - James Alfred Ewing - Life
James Alfred Ewing - Early Life. Born in Dundee, Scotland, the third son of a minister of the Free Church of Scotland and educated at W...   » Read the article

Encyclopedia - Intelligence In The American Revolutionary War: Encyclopedia Ii - Intelligence In The American Revolutionary War - Intelligence Techniques
Intelligence in the American Revolutionary War - Secrecy and Protection. The Committee of Secret Correspondence insisted that matters p...   » Read the article

Encyclopedia - Magic Cryptography: Encyclopedia Ii - Magic Cryptography - Decryption Process
There were several prior steps needed before any decrypt was ready for distribution: First, it had to be intercepted. The Japanese Forei...   » Read the article

Encyclopedia - Encryption: Encyclopedia Ii - Encryption - Ciphers
A cipher is an algorithm for performing encryption (and the reverse, decryption) — a series of well-defined steps that can be followed ...   » Read the article

Encyclopedia - Information Theory: Encyclopedia Ii - Information Theory - Basic Concepts For Discrete Channels
Information theory - Self-information. Shannon defined a measure of information content called the self-information or surprisal of a m...   » Read the article

Encyclopedia - Sigint: Encyclopedia Ii - Sigint - Sigint
SIGINT is actually a broad discipline under which multiple sub-disciplines fall. There are three major sub-disciplines that fall under SI...   » Read the article

Encyclopedia - Computer: Encyclopedia Ii - Computer - Digital Circuits
The conceptual design above could be implemented using a variety of different technologies. As previously mentioned, a stored program com...   » Read the article

Encyclopedia - History Of Cryptography: Encyclopedia Ii - History Of Cryptography - Modern Cryptography
History of cryptography - Shannon. The era of modern cryptography really begins with Claude Shannon, arguably the father of mathematica...   » Read the article

Encyclopedia - Colossus Computer: Encyclopedia Ii - Colossus Computer - Influence And Fate
The use to which the Colossi were put was of the highest secrecy, and the Colossus itself was highly secret, and remained so for many yea...   » Read the article

Encyclopedia - Data Encryption Standard: Encyclopedia Ii - Data Encryption Standard - Security And Cryptanalysis
Although more information has been published on the cryptanalysis of DES than any other block cipher, the most practical attack to date i...   » Read the article

Encyclopedia - Differential Cryptanalysis: Encyclopedia Ii - Differential Cryptanalysis - Origins Of Differential Cryptanalysis
The discovery of differential cryptanalysis is generally attributed to Eli Biham and Adi Shamir in the late 1980s, who published a number...   » Read the article

Encyclopedia - Cryptography: Encyclopedia Ii - Cryptography - Terminology
The study of how to circumvent the use of cryptography is called cryptanalysis, or codebreaking. Cryptography and cryptanalysis are somet...   » Read the article

Encyclopedia - Cross-correlation: Encyclopedia Ii - Cross-correlation - Properties
The cross-correlation is related to the convolution by: so that if either f or g is an even function. Also: ... See also:Cross...   » Read the article

Encyclopedia - Information Theory: Encyclopedia Ii - History
Claude E. Shannon (1916–2001) founded information theory with his classic paper "A Mathematical Theory of Communication", published in ...   » Read the article

Encyclopedia - Information Theory: Encyclopedia Ii - Applications
Information theory - Coding Theory. Coding theory is the most important and direct application of information theory. It can be subdivi...   » Read the article

Encyclopedia - Information Theory: Encyclopedia Ii - Related Concepts
Information theory - Measure Theory. Here is an interesting and illuminating connection between information theory and measure theory: ...   » Read the article

Encyclopedia - Information Theory: Encyclopedia Ii - Continuous Channels
Shannon information is appropriate for measuring uncertainty over a discrete space. Its basic measures have been extended by analogy to c...   » Read the article

Encyclopedia - Information Theory: Encyclopedia Ii - Mathematical Preliminaries
Information theory is based on and intimately connected with probability theory. In information theory, logarithms are used extensively. ...   » Read the article

Encyclopedia - Information Theory: Encyclopedia Ii - Channel Capacity
Let us return for the time being to our consideration of the communications process over a discrete channel. At this time it will be help...   » Read the article

Encyclopedia - Information Theory: Encyclopedia Ii - Source Theory
Any process that generates successive messages can be considered a source of information. Sources can be classified in order of increasin...   » Read the article

Encyclopedia - Information Theory: Encyclopedia Ii - Fundamental Theorem
Information theory - Statement Noisy-Channel Coding Theorem. 1. For every discrete memoryless channel, the channel capacity h...   » Read the article

Encyclopedia - Information Theory: Encyclopedia Ii - Basic Concepts For Discrete Channels
Information theory - Self-information. Shannon defined a measure of information content called the self-information or surprisal of a m...   » Read the article

Encyclopedia - Colossus Computer: Encyclopedia Ii - Colossus Computer - Purpose And Origins
The Colossus computers were used in the cryptanalysis of high-level German communications, messages which had been encrypted using the Lo...   » Read the article

Encyclopedia - Colossus Computer: Encyclopedia Ii - Colossus Computer - The Construction Of Colossus
Tommy Flowers, an engineer brought in to assist with machinery to break the Enigma machine, spent ten months building Colossus at the Pos...   » Read the article

Encyclopedia - Colossus Computer: Encyclopedia Ii - Colossus Computer - Design And Operation
Colossus used state-of-the-art vacuum tubes (valves), thyratrons and photomultipliers to optically read a paper tape and then applied a p...   » Read the article

Encyclopedia - Harvest Computer: Encyclopedia Ii - Harvest Computer - Programming
Harvest's most important mode of operation was called 'setup' mode, in which the processor was configured (with several hundred bits of i...   » Read the article

Encyclopedia - Harvest Computer: Encyclopedia Ii - Harvest Computer - Architecture
The equipment added to the Stretch computer consisted of the following special peripherials: IBM 7951 - Stream coprocessor IBM 7952 - Hi...   » Read the article

Encyclopedia - Harvest Computer: Encyclopedia Ii - Harvest Computer - Development
In April 1958, the final design for the NSA-customized version of IBM's Stretch computer had been approved, and the machine was installed...   » Read the article

Encyclopedia - Frequency Analysis: Encyclopedia Ii - Frequency Analysis - History And Usage
The first known recorded explanation of frequency analysis (indeed, of any kind of cryptanalysis) was given by 9th century Arab polymath ...   » Read the article

Encyclopedia - Cryptography: Encyclopedia Ii - Cryptography - History Of Cryptography
Main article: History of cryptography Cryptography has had a long and colourful history. Generally, the earliest forms of secret writing ...   » Read the article

Encyclopedia - Information Forensics: Encyclopedia Ii - Information Forensics - Methods And Standards
Established standards govern the creation, modification, operation and retirement of information systems. Standard methods however are co...   » Read the article

Encyclopedia - Intelligence In The American Revolutionary War: Encyclopedia Ii - Intelligence In The American Revolutionary War - Intelligence Operations
Main article: Intelligence Operations in the American Revolutionary War Intelligence operations included the usual sabotage, kidnapping, ...   » Read the article

Encyclopedia - Two-square Cipher: Encyclopedia Ii - Two-square Cipher - Using Two-square
The two-square cipher comes in two varieties - horizontal and vertical. The vertical two-square uses two 5 by 5 matrices one above the ot...   » Read the article

Encyclopedia - Intelligence In The American Revolutionary War: Encyclopedia Ii - Intelligence In The American Revolutionary War - Organization Of Intelligence
Intelligence in the American Revolutionary War - The Secret Committee. The Second Continental Congress had created a Secret Committee b...   » Read the article

Encyclopedia - Information Forensics: Encyclopedia Ii - Information Forensics - What Is And Is Not Information Forensics
Information forensics encompasses information systems forensics and computer forensics. Information forensics deals with system processes...   » Read the article

Encyclopedia - Cryptography: Encyclopedia Ii - Cryptography - Secure Communications
See also: Information security Cryptography is commonly used for securing communications. Desired properties can include: Confidentialit...   » Read the article