Authentication code

Data authentication To provide evidence that the data possessed by the system has not been altered or destroyed in an unauthorized manner. Examples of how data authentication may be assured include the use of an authentication code, or digital signature. ... 

We can view this mode as combination of the Counter mode and the Cipher Feedback mode (CTR+CFB). After processing all message blocks the cipher internal state (.S, ) depends linearly on the last block and non-linearly on all other message blocks (Mi), encryption key (K) and initialization vector (IV). In order to get Message Authentication Code (MAC) it is necessary to perform yet one blank encryption. The obtained base cipher output block or its part can be used as MAC. 

A similar work for authentication schemes was only published 15 years later In [GiMS74], the information-theoretic, i.e., absolute security of symmetric authentication schemes was defined. Schemes complying with this definition are often called authentication codes. Like Claude Shannon s work, [GiMS74] already contains both concrete constructions of authentication codes and lower bounds on the achievable efficiency, and in particular, the key length. In contrast to secrecy schemes, however, the upper and lower bounds are not identical furthermore, the constructions are less trivial. Therefore, there has been further research in this field. 

In particular, efficiently computable authentication codes where the key length only grows logarithmically with the length of the messages to be authenticated later were constructed in [WeCaSl]. An improvement of this scheme and an overview of the literature in this field can be found in [BJKS94]. 

BrSt88 Ernest F. Brickell, Doug R. Stinson Authentication Codes with Multiple Arbiters Eurocrypt 88, LNCS 330, Springer-Verlag, Berlin 1988, 51-55. 

Protect individual components from exploitation and develop strategies for active security protection appropriate for the device s use environment. Such strategies should include timely deployment of routine, validated security patches and methods to restrict software or firmware updates to authenticated code. Note The FDA typically does not need to review or approve medical device software changes made solely to strengthen cybersecurity. 

Taking into consideration the rapid evolution of the communication standards that include message authentication and integrity verification, we realize that constructions like HMAC, are widely used in the most popular cryptographic schemes since provision of a way to check the integrity of information transmitted over or stored in an unreliable medium is a prime necessity in the world of open computing and communications. Typically, message authentication codes are used between two parties that share a secret key in order to authenticate information transmitted between these parties. 

NIST, FIPS 198-1, (2007) a The Keyed-Hash Message Authentication Code (HMAC), US Dept of Commerce... 

There are also already proven solutions for these problems. A common HTTP scheme based on a Hash Message Authentication Code (HMAC, REC 2104) [10] may be used for authentication. 

The use of authentication checks at physical access points in order to establish that the machine-readable codes on tokens and PINs are assigned to the same individual. 

Personal Identification Number A PIN is an alphanumeric code or password used to authenticate the identity of an individual. 

Systems that use a password/ID code-based nonbiometrics electronic signature are common, and use both a PIN and a password as authentication and as an electronic signature. The combination of the PIN and password must be unique. Generally, companies and organizations ensure that the PIN is unique so that if, by coincidence, two persons create the same password, this does not result in two identical electronic signatures. Furthermore, firms generally establish unique (but not confidential) PINs. 

The second section reviews documentation in relation to CSV and the procedural controls required for regulated operations. Change management and control, training, and security (introducing key technology-driven services such as user/data authentication and access control), are followed by guidance on source code issues, and suppliers qualifications. 

In the paper we propose a new method of iris texture coding and feature extraction, and its application to internet security. We shortly introduce the iris coding method based on Zak-Gabor coefficients sequence, the routines for optimal iris features selection, and we show how these ideas may be implemented into a secure remote access system. A prototype of remote such authentication device was built and tested with the use of an iris database. 

The above scenario is generic and may be applied to iris-based authentication. In particular, iris recognition with Zak-Gabor iris coding methodology can be applied here. 

Internationally too, measures have been established to protect consumers and ensure the authenticity of the foods they purchase, namely the standards of the Codex Alimentarius ( food code ). These will be described in this section and in particular as they relate to edible fats and oils. However, in order to put this into context, some background information will be given first on the Codex Alimentarius organization and how it works. 

Fig. 2.1. The backbone structures of authentic and recombinant goat a-lactalbumin in the crystal form. The backbone of Mol A of the authentic protein, represented by a wire model, was superimposed on the backbone of the recombinant protein. Gray and black wires represent the authentic and recombinant proteins, respectively. The C -atom RMSD value between the two proteins was 0.54 A. The PDB codes for the authentic and recombinant proteins are 1HFY and 1HMK, respectively...

DNA is the biological blueprint material, which authentically carries all the necessary cellular information and passes it from generation to generation. Thus, it is essential for the cells to preserve the integrity of the DNA and keep it as error free as possible. One is amazed with the versatile DNA molecule, which dictates both the unique and the similar features of the offspring from its parents. What are the processes that take place in a cell to duplicate and interpret this genetic code into functional signals DNA is duplicated in a semiconservative fashion in a process called DNA replication. 

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