Cryptanalysis Techniques for Stream Cipher: A Survey <s> Side Channel Analysis Attack: <s> When the running time of a cryptographic algorithm is non-constant, timing measurements can leak information about the secret key. This idea, first publicly introduced by Kocher, is developed here to attack an earlier version of the CASCADE smart card. We propose several improvements on Kocher’s ideas, leading to a practical implementation that is able to break a 512-bit key in few hours, provided we are able to collect 300000 timing measurements (128-bit keys can be recovered in few seconds using a personal computer and less than 10000 samples). We therefore show that the timing attack represents an important threat against cryptosystems, which must be very seriously taken into account. <s> BIB001 </s> Cryptanalysis Techniques for Stream Cipher: A Survey <s> Side Channel Analysis Attack: <s> Cryptosystem designers frequently assume that secrets will be manipulated in closed, reliable computing environments. Unfortunately, actual computers and microchips leak information about the operations they process. This paper examines specific methods for analyzing power consumption measurements to find secret keys from tamper resistant devices. We also discuss approaches for building cryptosystems that can operate securely in existing hardware that leaks information. <s> BIB002 </s> Cryptanalysis Techniques for Stream Cipher: A Survey <s> Side Channel Analysis Attack: <s> Side-channel attacks are easy-to-implement whilst powerful attacks against cryptographic implementations, and their targets range from primitives, protocols, modules, and devices to even systems. These attacks pose a serious threat to the security of cryptographic modules. In consequence, cryptographic implementations have to be evaluated for their resistivity against such attacks and the incorporation of different countermeasures has to be considered. This paper surveys the methods and techniques employed in these attacks, the destructive effects of such attacks, the countermeasures against such attacks and evaluation of their feasibility and applicability. Finally, the necessity and feasibility of adopting this kind of physical security testing and evaluation in the development of FIPS 140-3 standard are explored. This paper is not only a survey paper, but also more a position paper. <s> BIB003 </s> Cryptanalysis Techniques for Stream Cipher: A Survey <s> Side Channel Analysis Attack: <s> Side-channel attacks on block ciphers and public key algorithms have been discussed extensively. However, there is only sparse literature about side-cannel attacks on stream ciphers. The few existing references mainly treat timing [8] and template attacks [10], or provide a theoretical analysis [6], [7] of weaknesses of stream cipher constructions. In this paper we present attacks on two focus candidates, Trivium and Grain, of the eSTREAM stream cipher project. The attacks exploit the resynchronization phase of ciphers. A novel concept for choosing initial value vectors is introduced, which totally eliminates the algorithmic noise of the device, leaving only the pure side-channel signal. This attack allows to recover the secret key with a small number of samples and without building templates. To prove the concept we apply the attack to hardware implementations of the ciphers. For both stream ciphers we are able to reveal the complete key. <s> BIB004
Generally there are two steps involved in developing any cryptographic primitive. First, it is defined as an abstract mathematical object. Thereafter this mathematical entity needs to be implemented in form of a program and in some cases these programs are further implemented in some specific hardware. These programs after implementation will be executed in a computing environment on processing units. These executions will present some specific characteristics. Side channel Analysis (SCA) refers to the attacks based on the physically observable characteristics during execution. Some of the common physical characteristics that are used for Side Channel Analysis are Power and Microprocessor time required for execution, electromagnetic radiation, heat dissipation and noise of the system etc. On the basis of above characteristics; there are different Side Channel attacks on ciphers in general and on stream cipher in particular. Some of powerful techniques, that generally used for Side Channel Analysis attacks are Simple Power analysis attack, Differential Power Analysis attack BIB004 BIB002 , Timing Analysis attack BIB001  , Electromagnetic Analysis attacks    and Acoustic Cryptanalysis  . Though there is no general countermeasure to these attacks but some of the possible countermeasures maybe noise addition, buffering of the output sequence, Physical shielding, reduction of signal size, eliminating the branch processing in implemented algorithm that will make the encryption time equivalent BIB003  and few more.