Abstract. PGP is built upon a Distributed Web of Trust in which a user's trustworthiness is established by others who can vouch through a digital signature for that user's identity. Preventing its wholesale adoption are a number of inherent weaknesses to include (but not limited to) the following: 1) Trust Relationships are built on a subjective honor system, 2) Only first degree relationships can be fully trusted, 3) Levels of trust are difficult to quantify with actual values, and 4) Issues with the Web of Trust itself (Certification and Endorsement). Although the security that PGP provides is proven to be reliable, it has largely failed to garner large scale adoption. In this paper, we propose several novel contributions to address the aforementioned issues with PGP and associated Web of Trust. To address the subjectivity of the Web of Trust, we provide a new certificate format based on Bitcoin which allows a user to verify a PGP certificate using Bitcoin identity-verification transactions -forming first degree trust relationships that are tied to actual values (i.e., number of Bitcoins transferred during transaction). Secondly, we present the design of a novel Distributed PGP key server that leverages the Bitcoin transaction blockchain to store and retrieve Bitcoin-Based PGP certificates. Lastly, we provide a web prototype application that demonstrates several of these capabilities in an actual environment.In a recent article, Yahoo announced its intentions to add an extension that will provide its customers with the ability to digitally sign and encrypt messages using Pretty Good Privacy (PGP). Yahoo plans to use a fork of Google's End to End OpenPGP plugin that is currently in development. Yahoo follows the likes of Google, Facebook and Microsoft, who also recently announced they would encrypt internal traffic in response to the Snowden spying revelations [1]. Traditional methods of securely sharing between two or more parties rely on the use of Public-Key Encryption within a Public Key Infrastructure (PKI). In a traditional PKI scheme, a certificate authority or certification authority (CA) is an entity that issues digital certificates. The digital certificate certifies the ownership of a public key by the named subject of the certificate. This allows others (relying parties) to rely upon signatures or assertions made by the private key that corresponds to the public key that is certified. In this model of trust relationships, a CA is a Trusted Third Party (TTP) that is trusted by both the

Cyclic triimidazole, C9H6N6 (1), was prepared by thermolysis of the easily prepared copper imidazolate framework solid, Cu(C3H3N2)2 (2), providing a convenient route to this potentially useful tecton for molecular design. Anhydrous 1 and a hydrate, 1·0.5H2O, were characterized by single-crystal X-ray diffraction. Hydrate 1·0.5H2O contains two crystallographically independent 1 molecules. Supramolecular structures of 1 and 1·0.5H2O feature stacking arrangements in which the 1 molecule deviates from idealized geometry. A 3-fold H-bond acceptor 1 forms an adduct with boric acid, 1·B(OH)3, which was also structurally characterized. This adduct is composed of hydrogen-bonded sheets of 1 and B(OH)3 molecules with sheet interplanar separations of 3.175(4) Å and B(OH)3 boron atoms positioned above and below the centroids of 1 in adjacent sheets. Unlike 1 and its hydrate, 1·B(OH)3 contains 1 molecules that display crystallographically required D 3h symmetry. Anhydrous 1 crystallizes in the triclinic system, space group P1̅, with a = 7.2138(12), b = 8.3667(15), c = 8.8361(13) Å, α = 99.826(13), β = 113.825(10), γ = 110.721(11)°, V = 424.55(12) Å3, Z = 2; 1 2 ·H2O (or 1·0.5H2O), triclinic, P1̅, a = 7.5608(3), b = 7.5669(5), c = 15.8436(8) Å, α = 84.504(3), β = 81.269(3), γ = 87.038(3)°, V = 891.18(8) Å3, Z = 2; 1·B(OH)3, trigonal, P3̅, a = 10.1186(3), b = 10.1186(3), c = 6.3488(4) Å, α = 90, β = 90, γ = 120°, V = 562.94(4) Å3, Z = 2.

Water-free rare earth(III) hexacyanoferrate(III) complexes, {Ln(DMF)(6)(mu-CN)(2)Fe(CN)(4)}(infinity) (DMF = N,N-dimethylformamide; Ln = Sm, 1; Eu, 2; Gd, 3; Tb, 4; Dy, 5; Ho, 6; Er, 7; Tm, 8; Yb, 9; Lu, 10; Y, 11; La, 12; Ce, 13; Pr, 14; Nd, 15), were synthesized in dry DMF through the metathesis reactions of [(18-crown-6)K](3)Fe(CN)(6) with LnX(3)(DMF)(n) (X = Cl or NO(3)). Anhydrous DMF solutions of LnX(3)(DMF)(n) were prepared at room temperature from LnCl(3) or LnX(3).nH(2)O under a dynamic vacuum. All compounds were characterized by IR, X-ray powder diffraction (except for 10), and single crystal X-ray diffraction (except for 2, 7, 10). Infrared spectra reveal that a monotonic, linear relationship exists between the ionic radius of the lanthanide and the nu(mu-CN) stretching frequency of 1-10, 12-15 while 11 deviates slightly from the ionic radius relationship. X-ray powder diffraction data are in agreement with powder patterns calculated from single crystal X-ray diffraction results, a useful alternative for bulk sample confirmation when elemental analysis data are difficult to obtain. Eight-coordinate Ln(III) metal centers are observed for all structures. trans-cyanide units of [Fe(CN)(6)](3-) formed isocyanide linkages to Ln(III) resulting in one-dimensional polymeric chains. Structures of compounds 1-9 and 11 are isomorphous, crystallizing in the space group C2/c. Structures of compounds 12-15 are also isomorphous, crystallizing in the space group P2/n. One unique polymeric chain exists in the structures of 1-9 and 11 while two unique polymeric chains exist in structures of 12-15. One of the polymeric chains of 12-15 is similar to that observed for 1-9, 11 while the other is more distorted and has a shorter Ln-Fe distance. Magnetic susceptibility measurements for compounds 3-6, 8, 11 were performed on polycrystalline samples of the compounds.

With the advent of cloud computing, a number of cloud providers have arisen to provide Storage-as-a-Service (SaaS) offerings to both regular consumers and business organizations. SaaS (different than Software-as-a-Service in this context) refers to an architectural model in which a cloud provider provides digital storage on their own infrastructure. Three models exist amongst SaaS providers for protecting the confidentiality of data stored in the cloud: 1) no encryption (data is stored in plain text), 2) server-side encryption (data is encrypted once uploaded), and 3) client-side encryption (data is encrypted prior to upload). Through a combination of a Network and Source Code Analysis, this paper seeks to identify weaknesses in the third model, as it claims to offer 100% user data confidentiality throughout all data transactions. The weaknesses we uncovered primarily center around the fact that the cloud providers we evaluated (Wuala, Tresorit, and Spider Oak) were each operating in a Certificate Authority capacity to facilitate data sharing. In this capacity, they assume the role of both certificate issuer and certificate authorizer as denoted in a Public-Key Infrastructure (PKI) scheme -which gives them the ability to view user data contradicting their claims of 100% data confidentiality. We have collated our analysis and findings in this paper and explore some potential solutions to address these weaknesses in these sharing methods. The solutions proposed are a combination of best practices associated with the use of PKI and other cryptographic primitives generally accepted for protecting the confidentiality of shared information.

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