Mark G. Karpovsky

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We investigate a new class of codes for the optimal covering of vertices in an undirected graphG such that any vertex in G can be uniquely identified by examining the vertices that cover it. We define a ball of radius t centered on a vertex v to be the set of vertices in G that are at distance at most t from v: The vertex v is then said to cover itself and(More)
Network calculus is known to apply in general only to feedforward routing networks, i.e., networks where routes do not create cycles of interdependent packet flows. In this paper, we address the problem of using network calculus in networks of arbitrary topology. For this purpose, we introduce a novel graph-theoretic algorithm, called turn-prohibition (TP),(More)
All known results on covering radius are presented, as well as some new results. There are a number of upper and lower bounds, including asymptotic results, a few exact determinations of covering radius, some extensive relations with other aspects of coding theory through the Reed-Muller codes, and new results on the least covering radius of any linear [II,(More)
We present a method of protecting a hardware implementation of the Advanced Encryption Standard (AES) against a side-channel attack known as Differential Fault Analysis attack. The method uses systematic nonlinear (cubic) robust error detecting codes. Errordetecting capabilities of these codes depend not just on error patterns (as in the case of linear(More)
Ethernet networks rely on the so-called spanning tree protocol (IEEE 802.1d) in order to break cycles, thereby avoiding the possibility of infinitely circulating packets and deadlocks. This protocol imposes a severe penalty on the performance and scalability of large Gigabit Ethernet backbones, since it makes inefficient use of expensive fibers and may lead(More)
Ethernet networks rely on the so-called spanning tree protocol (IEEE 802.1d) in order to break cycles, thereby avoiding the possibility of infinitely circulating packets and deadlocks. This protocol imposes a severe penalty on the performance and scalability of large Gigabit Ethernet backbones, since it makes inefficient use of fibers and may lead to(More)
We present two architectures for protecting a hardware implementation of AES against side-channel attacks known as Differential Fault Analysis attacks. The first architecture, which is efficient for faults of higher multiplicity, partitions the design into linear (XOR gates only) and nonlinear blocks and uses different protection schemes for these blocks.(More)
A code C detects error e with probability 1-Q(e),ifQ(e) is a fraction of codewords y such that y, y+e/spl isin/C. We present a class of optimal nonlinear q-ary systematic (n, q/sup k/)-codes (robust codes) minimizing over all (n, q/sup k/)-codes the maximum of Q(e) for nonzero e. We also show that any linear (n, q/sup k/)-code V with n /spl les/2k can be(More)
Cryptographic devices are vulnerable to fault injection attacks. All previous countermeasures against fault injection attacks based on error detecting codes assume that the attacker cannot simultaneously control the fault-free outputs of a device-under-attack and error patterns. For advanced attackers who are able to control both of the above two aspects,(More)