KeeLoq is a block cipher used in numerous widespread passive entry and remote keyless entry systems as well as in various component identification applications. The KeeLoq algorithm has a 64-bit key and operates on 32-bit blocks. It is based on an NLFSR with a nonlinear feedback function of 5 variables. In this paper a key recovery attack with complexity of about 2 steps is proposed (one step i...

This paper describes the design of the random number generator (RNG) in the Caernarvon high assurance smart card operating system. Since it is used in the generation of cryptographic keys and other sensitive materials, the RNG has a number of stringent security requirements that the random bits must be of good quality i.e. the bits must not be predictable or biased. To this end, a number of sta...

We present several weaknesses in the key scheduling algorithm of RC4 when the secret key contains an initialization vector – a cryptographic scheme typically used by the WEP and WPA protocols to protect IEEE 802.11 wireless communications. First, we show how the previously discovered key recovery attacks can be improved by reducing the dependency between the secret key bytes. Then, we describe ...

Problem statement: A block ciphers provides confidentiality in cryptography but cryptanalysis of the classical block ciphers demonstrated some old weaknesses grabbing a partial key in any stage of encryption procedure leads to reconstructing the whole key. Exhaustive key search shows that key generation should be indeterminist and random for each round. Matching cipher-text attack shows that la...

Authenticated key exchange protocols are of fundamental importance in securing communications and are now extensively deployed for use in various real-world network applications. In this work, we reveal major previously unpublished security vulnerabilities in the password-based authenticated three-party key exchange protocol according to Lee and Hwang (2010): (1) the Lee-Hwang protocol is susce...

At Crypto ’88, Matsumoto, Kato and Imai proposed a protocol, known as RSA-S1, in which a smart card computes an RSA signature, with the help of an untrusted powerful server. There exist two kinds of attacks against such protocols: passive attacks (where the server does not deviate from the protocol) and active attacks (where the server may return false values). Pfitzmann and Waidner presented a...

Since two different types of side channel attacks based on passive information leakage and active fault injection are independently considered as implementation threats on cryptographic modules, most countermeasures have been separately developed according to each attack type. But then, Amiel et al. proposed a combined side channel attack in which an attacker combines these two methods to recov...

Mobile ad hoc networks (MANETs) are a set of mobile nodes which over a shared wireless medium communicate with each other without the presence of a predefined infrastructure or a central authority. [1]. The absence of a central management agency or a fixed infrastructure is a key feature of MANETs. Security issues in MANET are a challenging task nowadays. MANETs are vulnerable to passive attack...

In this paper, we report extremely fast and optimised active and passive attacks against the old IEEE 802.11 wireless communication protocol WEP. This was achieved through a huge amount of theoretical and experimental analysis (capturing WiFi packets), refinement and optimisation of all the former known attacks and methodologies against RC4 stream cipher in WEP mode. We support all our claims b...