Learn More
—We investigate a new class of codes for the optimal covering of vertices in an undirected graph G 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(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)
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)
— We will say that code C detects error e with probability 1 − Q(e), if Q(e) is a fraction of codewords y such that y, y + e ∈ C. We present a class of optimal nonlinear q-ary systematic (n, k)-codes (robust codes) minimizing over all (n, k)-codes maxima of Q(e) over all e = 0. We will also show that any linear (n, k))-code Vwith n ≤ 2k can be modified into(More)
The early propagation effect found in many logic gates is a potential source of data-dependent power consumption. We show that the effect and the corresponding power dependency can be targeted for successful power analysis attacks in cryptographic hardware. Many of the current balanced gate designs did not directly consider the effect and are vulnerable to(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)
Balanced gates are an effective countermeasure against power analysis attacks only if they can be guaranteed to maintain their power balance. Traditional testing and reliability methods are used primarily only to ensure the correctness of the logical functionality and not the balance of a circuit. Due to the hardware redundancy in balanced gate designs,(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)