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

Supramolecular chemistry is today a major thrust area, a significant part of which is based on the use of metal atoms or ions as key elements in promoting the assembly of and dictating the main structural features of the supramolecular products. Most of the work has been done with single metal atoms or ions in this role, but considerable success has already been achieved by employing M-M bonded dimetal entities instead. We review here the work done in our laboratory. Metal-metal bonded cationic complexes of the [M(2)(DAniF)(n)(MeCN)(8-2n)]((4-n)+) type, where M = Mo or Rh and DAniF is an N,N'-di-p-anisylformamidinate anion, have been used as subunit precursors and then linked by various equatorial and axial bridging groups such as polycarboxylate anions, polypyridyls, and polynitriles. Characterization of the products by single-crystal X-ray diffraction, CV, DPV, NMR, and other spectroscopic techniques has revealed the presence of discrete tetranuclear (pairs or loops), hexanuclear (triangles), octanuclear (squares), and dodecanuclear (cages) species and one-, two-, or three-dimensional molecular nanotubes. These compounds display a rich electrochemical behavior which is affected by the nature of the linkers.

Extensive chemical, spectrophotometric, and x-ray structural studies have shown that trivalent rhenium is strongly homophilic-that is, it tends to form bonds to other Re(111) atoms-and it forms at least three different series of [ReX(4)](n)(n-) complexes. The mononuclear, square complex, [ReBr(4)](-), adds two water molecules to give trans-[ReBr(4)(H(2)O)(2)](-). The binuclear complexes [Re(2)Cl(8)](2-) and [Re(2)Br(8)](2-) have strong Re-Re bonds, unsupported by halide bridges. The trinuclear species, [Re(3)X(12)](3-) or Re(3)X(9)L(3), contain the triangular Re(3)X(9) clusters. Use of ReCI(3) appears always to lead directly to products containing Re(3)Cl(9); this unit exists in ReCl(3) itself and does not appear to be kinetically labile. The [Re(2)X(8)](2-) ions are obtained by reduction of ReO(4)(-) in aqueous HCl or HBr. Salts of [ReBr(4)(H(2)O)(2)](-) can be obtained directly from solutions of ReBr(3) in HBr along with numerous other compounds, some containing trinuclear clusters.

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