Internal state recovery of Grain v1 employing guess-and-determine attack

2017 ◽  
Vol 11 (6) ◽  
pp. 363-368 ◽  
Author(s):  
Zhen Ma ◽  
Tian Tian ◽  
Wen-Feng Qi
2021 ◽  
Author(s):  
Orhun Kara

Tradeoff attacks on symmetric ciphers can be considered as the generalization of the exhaustive search. Their main objective is reducing the time complexity by exploiting the memory after preparing very large tables at a cost of exhaustively searching all the space during the precomputation phase. It is possible to utilize data (plaintext/ciphertext pairs) in some cases like the internal state recovery attacks for stream ciphers to speed up further both online and offline phases. However, how to take advantage of data in a tradeoff attack against block ciphers for single key recovery cases is still unknown. We briefly assess the state of art of tradeoff attacks on symmetric ciphers, introduce some open problems and discuss the security criterion on state sizes. We discuss the strict lower bound for the internal state size of keystream generators and propose more practical and fair bound along with our reasoning. The adoption of our new criterion can break a fresh ground in boosting the security analysis of small keystream generators and in designing ultra-lightweight stream ciphers with short internal states for their usage in specially low source devices such as IoT devices, wireless sensors or RFID tags.


Author(s):  
Thomas Fuhr ◽  
María Naya-Plasencia ◽  
Yann Rotella

In this article we study the security of the authenticated encryption algorithm Ketje against divide-and-conquer attacks. Ketje is a third-round candidate in the ongoing CAESAR competition, which shares most of its design principles with the SHA-3 hash function. Several versions of Ketje have been submitted, with different sizes for its internal state. We describe several state-recovery attacks on the smaller variant, called Ketje Jr. We show that if one increases the amount of keystream output after each round from 16 bits to 40 bits, Ketje Jr becomes vulnerable to divide-and-conquer attacks with time complexities 271.5 for the original version and 282.3 for the current tweaked version, both with a key of 96 bits. We also propose a similar attack when considering rates of 32 bits for the non-tweaked version. Our findings do not threaten the security of Ketje, but should be taken as a warning against potential future modifications that would aim at increasing the performance of the algorithm.


2012 ◽  
Vol 112 (21) ◽  
pp. 805-810 ◽  
Author(s):  
Miodrag J. Mihaljević ◽  
Sugata Gangopadhyay ◽  
Goutam Paul ◽  
Hideki Imai

2012 ◽  
Vol 6 (2) ◽  
pp. 55 ◽  
Author(s):  
M.J. Mihaljević ◽  
S. Gangopadhyay ◽  
G. Paul ◽  
H. Imai

2012 ◽  
Author(s):  
Susanne Kristen ◽  
Beate Sodian ◽  
Maria Licata ◽  
Claudia Thoermer ◽  
Diane Poulin‐Dubois

2017 ◽  
Vol 21 (4) ◽  
pp. 154-164
Author(s):  
A. N. Gutorova

Non-state factors begin to play more and more significant role in processes of global management. The international non-governmental organizations are on a special place among them (INGO). In the last decade they are growing noticeably. In this regard it is necessary to study the role and the meaning of international non-governmental organizations in the process of global management. It is a vital need of modern science. Attempts to elaborate definition of the concept "international non-governmental organization" were made repeatedly but all developed concepts have certain shortcomings (don't reflect the legal nature of INGO, membership, activity purposes, etc.). The bulk of non-governmental organizations are created for the solution of specific problems or work within a certain perspective. Today these organizations actively deal with issues connected with humanitarian assistance, protection of human rights and environmental protection, providing peace and safety, participate in educational programs, sports projects. They provide analysis and expert assessment of various problems, including global problems, act as mechanism of "early notification" and promote control of international agreements execution. But, without looking, for rather positive role of MNPO in their activity there are also certain problems. INGO is often accused in internal state affairs. Their activity often has politized character.


Author(s):  
Laura Hurley

The inferior colliculus (IC) receives prominent projections from centralized neuromodulatory systems. These systems include extra-auditory clusters of cholinergic, dopaminergic, noradrenergic, and serotonergic neurons. Although these modulatory sites are not explicitly part of the auditory system, they receive projections from primary auditory regions and are responsive to acoustic stimuli. This bidirectional influence suggests the existence of auditory-modulatory feedback loops. A characteristic of neuromodulatory centers is that they integrate inputs from anatomically widespread and functionally diverse sets of brain regions. This connectivity gives neuromodulatory systems the potential to import information into the auditory system on situational variables that accompany acoustic stimuli, such as context, internal state, or experience. Once released, neuromodulators functionally reconfigure auditory circuitry through a variety of receptors expressed by auditory neurons. In addition to shaping ascending auditory information, neuromodulation within the IC influences behaviors that arise subcortically, such as prepulse inhibition of the startle response. Neuromodulatory systems therefore provide a route for integrative behavioral information to access auditory processing from its earliest levels.


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