Knudsen and Mathiassen (2004) give some experimental evidence that indicate that the key schedule plays a part in providing strength against linear and differential cryptanalysis. For toy Feistel ciphers, it was observed that those with complex and well-designed key schedules can reach a uniform distribution for the probabilities of differentials and linear hulls faster than those with poorly-designed key schedules.
EFF DES cracker
In cryptography, the EFF DES cracker (nicknamed "Deep Crack") is a machine built by the Electronic Frontier Foundation (EFF) to perform a brute force search of DES cipher's key space — that is, to decrypt an encrypted message by trying every possible key. The aim in doing this was to prove that DES's key is not long enough to be secure.
The DES uses a 56-bit key, meaning that there are 2 possible keys under which a message can be encrypted. This is approximately 7.21 (more than 72 quadrillion). When DES was approved as a federal standard in 1976, a machine fast enough to test such a number of keys in a reasonable time would have cost an unreasonable amount of money to build.
Classified information
Classified information is sensitive information to which access is restricted by law or regulation to particular classes of people. A formal security clearance is required to handle classified documents or access classified data. The clearance process requires a satisfactory background investigation. There are typically several levels of sensitivity, with differing clearance requirements. This sort of hierarchical system of sharing information among a group of people is almost used by every national government. The operation of assigning the level of sensitivity to data is called data classification.
The purpose of classification is to protect information from being used to damage or cause danger to national security. Classification formalizes what constitutes a "state secret" and deals with different levels of protection based on the expected damage the information might cause if it reached the wrong hands.
Certain non-government organizations and corporations also have their own secret information, normally referred to as trade secrets.
Although the classification systems vary from country to country, most have levels corresponding to the following British definitions (from the highest level to lowest):
Depending on the level of classification there are different rules controlling the level of clearance needed to view such information, and how it must be stored, transmitted, and destroyed. Additionally, access is restricted on a "need to know" basis. Simply possessing a clearance does not automatically authorize the individual to view all material classified at that level or below that level. The individual must present a legitimate "need to know" in addition to the proper level of clearance.
Security clearance
A security clearance is a status granted (approved) to individuals allowing them access to classified information, e.g. state secrets. It is something like permission or a license. The term "security clearance" is also sometimes used in private organizations that have a formal process of selecting employees to access ""sensitive information"".
A clearance by itself is normally not sufficient to gain access; the organization must determine that the cleared person ""needs to know"" the information. No one is supposed to be granted access to classified information only because of rank, position, or a security clearance.
Sensitive information
Sensitive information is information or knowledge that might result in loss of an advantage or level of security if exposed to others who might be unfriends or have low or unknown trustability.
Loss, misuse, modification or unauthorized access to sensitive information can negatively affect the privacy of an individual, trade secrets of a business or even the security, internal and foreign affairs of a nation depending on the level of sensitivity and nature of the information.
The term classified information generally refers to information that is subject to special security classification regulations imposed by many national governments. The term "Unclassified" as used in the below refers to information that is not subject to security classification regulations. Information can be reclassified to a different level or declassified (made available to the public) depending on changes of situation or new intelligence.
Trade secret
A trade secret is a formula, practice, process, design, instrument, pattern, or a collection of information which is not generally known, invented or created, by which a business can obtain an economic advantage over competitors or customers. In some jurisdictions, such secrets are referred to as "confidential information" or "classified information".
With its broad definition of eligible subject matter, trade secret law protects a wide range of valuable information, including information that would not be eligible for protection under existing patent, trademark, or copyright law. This could include formulae and recipes, proprietary databases, business processes and methods, information about costs, pricing, margins, overhead, manufacturing processes, proprietary computer software programs, customer lists, and strategic plans and marketing programs.
There are three factors that are common to all definitions of a trade secret, a trade secret is information that:
The unauthorized acquisition, use, or disclosure of such secret information in a manner contrary to honest commercial practices by others is regarded as an unfair practice and a violation of the trade secret protection.
Rock Steady
Rock Steady is the fifth studio album by the American alternative rock band No Doubt. It was released on December 11, 2001. The album was influenced a lot by reggae, dancehall, and electronica, compared to their previous albums. A lot of music critics saw this and gave the album good reviews. For example, "Rolling Stone" magazine put the album as the 316th greatest album of all time in their book "Rolling Stone's List of the 500 Greatest Albums of All Time". It was nominated for Best Pop Vocal Album at the 2003 Grammy Awards. Four singles were released from the album. The first single, "Hey Baby", won the Grammy Award for Best Pop Performance by a Duo or Group with Vocal. The second single was nominated for Best Dance Recording. The third single, "Underneath It All", was released August 15 2002. It won a Grammy Award for Best Pop Performance by a Duo or Group with Vocal at the 2004 Grammy Awards. The album's last single, "Running", was released July 1 2003.
The iTunes version of the album has two extra songs.
Meet-in-the-middle attack
The Meet-in-the-middle attack is a cryptographic attack which, like the birthday attack, makes use of a space-time tradeoff. While the birthday attack attempts to find two values in the domain of a function that map to the same value in its range, the meet-in-the-middle attack attempts to find a value in each of the ranges and domains of the composition of two functions such that the forward mapping of one through the first function is the same as the inverse image of the other through the second function—quite literally meeting in the middle of the composed function.