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AES: Other attacks

It is clear that so far, none of the attacks carried out against full-AES has been successful, these attacks usually focus on reducing rounds. Many authors claim that none of the following types of attacks have been more effective than an exhaustive-key search: Linear cryptanalysis Differential Cryptanalysis Truncated diferencials Interpolation attacks Square attack However, the ordered structure and the deep mathematical basis that AES uses, make it an object of study for new attacks proposals such as algebraic attacks. These attacks consist on propose an equation system, and with the unknowns of the system, it can deduce the key; one…
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Femto-cell: challenges in managing interferences

Some studies show that over 50% of voice calls and 70% of the data traffic comes from inside [1], voice calls do not require high bandwidth, but certain quality parameters are require to ensure the voice recognition of users at the other end of the communication, on the contrary, the data traffic requires high transmission rates to send information with a lot of megabytes, such as multimedia applications require, to name one example. One way to ensure high transmission rates on radio systems, is to maintain high signal quality at both ends of the communication, and hence, mitigate the effects…
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Attack on AES: Omission of MixColumns

As we mentioned in a previous article, rounds that make up the AES algorithm can be divided into three different categories: initial rounds, standard round and final round. When encryption, the information is subjected to a different number of rounds (10, 12 and 14 respectively) in each case depending on the length of the key (128, 192 and 256 respectively). Each such round is made up of combinations of transformations, the possible transformations include: ByteSub, ShiftRow, MixColumns and AddRoundKey. Figure # 1 shows the relationship of the transformation and corresponding rounds.   Figure # 1: Distribution of the transformations in…
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How to obtain a traffic model for VoIP?

In order to perform estimations of a traffic model for multimedia flows, it is necessary for the researcher to have precise control of the test environment, minimizing errors and interference that may occur, leaving a test scenario that allows a smooth development to the application to be modeled. As an example, we have selected a VoIP traffic which is quite easy to interpret and it provides some of the things that must be done.   Scenario for testing Figure # 1 shows the diagram used for testing in order to obtain the pattern of traffic on the transmission of voice…
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Cryptographic attack on AES: Impossible Differential Attack

Some time ago, I read an interesting article of a "successful attack" against AES, the famous symmetric-key algorithm. Raphael C.-W. Phan [1] presented a seven rounds "impossible differential attack" for AES-192 and AES-256. Someone may ask: what kind of attack is this?, well, it is a crypt-analysis that takes advantage of the differences that are impossible to be, in a data block through encryption, in order to discover the key?. Without going into many details of the method used, below I comment some of the most important results of this study. The attack involves taking pairs of identical texts in…
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