Chae Hoon Lim

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A new precomputation method is presented for computing gR for a fixed element g and a randomly chosen exponent R in a given group. Our method is more efficient and flexible than the previously proposed methods, especially in the case where the amount of storage available is very small or quite large. It is also very efficient in computing gRyB for a small(More)
RFID technology arouses great interests from both its advocates and opponents because of the promising but privacy-threatening nature of low-cost RFID tags. A main privacy concern in RFID systems results from clandestine scanning through which an adversary could conduct silent tracking and inventorying of persons carrying tagged objects. Thus, the most(More)
Consider the well-known oracle attack: Somehow one gets a certain computation result as a function of a secret key from the secret key owner and tries to extract some information on the secret key. This attacking scenario is well understood in the cryptographic community. However, there are many protocols based on the discrete logarithm problem that turn(More)
The block cipher CRYPTON has been proposed as a candidate algorithm for the Advanced Encryption Standard (AES). To x some minor weakness in the key schedule and to remove some undesirable properties in S-boxes, we made some changes to the AES proposal, i.e., in the S-box construction and key scheduling. This paper presents the revised version of CRYPTON and(More)
This paper presents a new 64-bit block cipher mCrypton with three key size options (64 bits, 96 bits and 128 bits), specifically designed for use in resource-constrained tiny devices, such as low-cost RFID tags and sensors. It’s designed by following the overall architecture of Crypton but with redesign and simplification of each component function to(More)
In this paper we consider the problem of reducing the computational load by use of restricted key parameters in the RSA system. We present various methods for generating RSA key parameters that can produce the secret key with much smaller binary weight than the ordinary case. This will greatly reduce the number of multiplications required for RSA decryption(More)
This paper presents a security-enhanced variant of LEAP+, called LEAP++. The proposed scheme not only improves the security against node capture attacks but also provides additional robustness against denial-of-service and node fabrication attacks. It also provides an easy way to detect in many cases, if not all, node replication and wormhole attacks during(More)