Abstract-This report is in two parts. In the first part I talk about Trusted Computing, while in the second part the focus is on pseudonymity.In today's world, security is of primary concern. Data of ever increasing value is being created and stored on PC's. At the same time, more and more vulnerabilities are being found in existing software . Till now, the main focus of security has been servers and networks, while clients have remained relatively unprotected. Also, most of the mechanisms in place for client security are software based. It is increasingly being felt that client security should be given much more importance and that a purely software based mechanism is inadequate in providing the required level of security. It was with this in mind that people and organizations started exploring the idea of security through hardware enhancements and a whole new paradigm of Trusted Computing was born. The idea was to come up with appropriate hardware modifications that would help in providing security against software attacks on clients. Here, I will present the suggested enhancements and look at the proposed security mechanism. This technology is no longer on paper and companies such as Intel, IBM etc. have started selling PC's with some of the required enhancements.An important component of Trusted Computing is Attestation. This is the ability of a system to prove its security properties to a remote system. However, this immediately raises questions of privacy. Although we want to prove our credentials to a remote host, we do not want it to know any other identifying information about us. This leads us to the more general problem of protecting user privacy. Users want the ability to control the information that others know about them and also to be able to monitor and control its use. Currently, the way computers are used to carry out transactions, user privacy is being compromised since organisations and other users get to know much more information than what is necessary. We need anonymity in transactions. At the same time, we want to safeguard against malicious users who try to exploit the system. In this report, I will present a simple anonymous credential system proposed by Chaum [1]. A credential system is a system in which users can obtain credentials from some organizations and demonstrate their possession. It is said to be anonymous when no one (apart from maybe a few trusted third parties) can say whether two transactions are being carried out by the same user. I will conclude by presenting the basic mathematics underlying the anonymous credential system proposed by Camenisch and Lysyanskaya [2] that is actually used in the above security framework (Trusted Computing) for achieving anonymous attestation. Trusted Computing

This report describes new, readily accessible copper(I) complexes that can exhibit unusually long-lived, high quantum yield emissions in fluid solution. The complexes are of the form [Cu(NN)(POP)]+ where NN denotes 1,10-phenanthroline (phen), 2,9-dimethyl-1,10-phenanthroline (dmp) or 2,9-di-n-butyl-1,10-phenanthroline (dbp) and POP denotes bis[2-(diphenylphosphino)phenyl] ether. Modes of characterization include X-ray crystallography and cyclic voltammetry. The complexes each have a pseudotetrahedral coordination geometry and a Cu(II)/Cu(I) potential upward of +1.2 V vs Ag/AgCl. In room-temperature dichloromethane solution, charge-transfer excited states of the dmp and dbp derivatives exhibit respective emission quantum yields of 0.15 and 0.16 and corresponding excited-state lifetimes of 14.3 and 16.1 mus, respectively. Despite the fact that coordinating solvents usually quench charge-transfer emission from copper systems, the photoexcited dmp (dbp) complex retains a lifetime of 2.4 mus (5.4 mus) in methanol.

The pseudotetrahedral complexes [Cu(NN)(DPEphos)]BF(4), where DPEphos = bis[2-(diphenylphosphino)phenyl]ether and NN = 1,10-phenanthroline (1), 2,9-dimethyl-1,10-phenanthroline (2), 2,9-di-n-butylphenanthroline (3), or two dimethylcyanamides (4), and NiCl(2)(DPEphos) (5) have been synthesized and structurally characterized by X-ray crystallography and their solution properties examined by use of a combination of cyclic voltammetry, NMR spectroscopy, and electronic absorption spectroscopy. Complexes 1-4 possess a reversible Cu(II)/Cu(I) couple at potentials upward of +1.2 V versus Ag/AgCl. Compounds 1-3 exhibit extraordinary photophysical properties. In room-temperature dichloromethane solution, the charge-transfer excited state of the dmp (dbp) derivative exhibits an emission quantum yield of 0.15 (0.16) and an excited-state lifetime of 14.3 mus (16.1 mus). Coordinating solvents quench the charge-transfer emission to a degree, but the photoexcited dmp complex 2 retains a lifetime of over a microsecond in acetone, methanol, and acetonitrile.

Cryogenic matrix photolysis of 3,5-dichloro-2,4,6-triazidopyridine, 3-chloro-5-cyano-2,4,6-triazidopyridine, 3,5-dicyano-2,4,6-triazidopyridine, and 3,5-difluoro-2,4,6-triazidopyridine (1-4) gives rise to ESR spectral peaks of various triplet mononitrene, quintet dinitrene, and septet trinitrene species. The quintet 2,4dinitrenes derived from 1-2 and 4 have zero-field splittings (zfs) of |D/hc| ∼ 0.22-0.24 cm -1 , similar to values observed elsewhere for m-phenylene dinitrenes. 3,5-Dicyano-2,4,6-triazidopyridine (3) photolysis gives only a weak ESR signal corresponding to a mononitrene with a zfs of |D/hc| ∼ 1.22 cm -1 . The spectrum from 1 also shows a 2,6-dinitrene with |D/hc| ) 0.283 cm -1 , |E/hc| ) 0.036 cm -1 , which illustrates the effects of heteroatom perturbation upon the zfs of a geometrically rigid m-arylene dinitrene. Spectral peaks for unusual septet 2,4,6-trinitrenopyridines derived from complete deazetation of 1-2 were also identified by simulation of the septet spectra. The zfs parameters for the trinitrenes were estimated to be |D/hc| ∼ 0.1 cm -1 , with small E-values in both cases. Experimental and computational results support high spin ground states for the dinitrene and trinitrene species.