The authors have investigated the diffusion enhancement mechanism of BED (boron enhanced diffusion), wherein the boron diffusivity is enhanced three to four times over the equilibrium diffusivity at 1,050 C in the proximity of a silicon layer containing a high boron concentration. It is shown that BED is associated with the formation of a fine-grain polycrystalline silicon boride phase within an initially amorphous Si layer having a high B concentration. For 0.5 keV B{sup +}, the threshold implantation dose which leads to BED lies between 3 {times} 10{sup 14} and of 1 {times} 10{sup 15}/cm{sup {minus}2}. Formation of the shallowest possible junctions by 0.5 keV B{sup +} requires that the implant dose be kept lower than this threshold.

This paper presents a graph based approach to network vulnerability analysis. The method is flexible, allowing analysis of attacks from both outside and inside the network. It can analyze risks to a specific network asset, or examine the universe of possible consequences following a successful attack. The analysis system requires as input a database of common attacks, broken into atomic steps, specific network configuration and topology information, and an attacker profile. The attack information is matched with the network configuration information and an attacker profile to create a superset attack graph. Nodes identify a stage of attack, for example the class of machines the attacker has accessed and the user privilege level he or she has compromised. The arcs in the attack graph represent attacks or stages of attacks. By assigning probabilities of success on the arcs or costs representing level of effort for the attacker, various graph algorithms such as shortest path algorithms can identify the attack paths with the highest probability of success.

Data authentication as provided by digital signatures is a well known technique for verifying data sent via untrusted network links. Recent work has extended digital signatures to allow jointly generated signatures using threshold techniques. In addition, new proactive mechanisms have been developed to protect the joint private key over long periods of time and to allow each of the parties involved to verify the actions of the other parties. In this paper, the authors describe an application in which proactive digital signature techniques are a particularly valuable tool. They describe the proactive DSA protocol and discuss the underlying software tools that they found valuable in developing an implementation. Finally, the authors briefly describe the protocol and note difficulties they experienced and continue to experience in implementing this complex cryptographic protocol.

Compilation of monthly reports from departments in the city of San Antonio, Texas providing statistics, project updates, and other information about services and activities.