It has been conventional wisdom that, for e-commerce to fulfil its potential, each party to a transaction must be confident about the identity of the others. Digital signature technology, based on public key cryptography, has been claimed as appropriate means to achieve this aim. Digital signatures do little, however, unless a substantial 'public key infrastructure' (PKI) is in place, such that...

Attempts to understand the physiological roles of the protein kinase inhibitor (PKI) proteins have been hampered by a lack of knowledge concerning the molecular heterogeneity of the PKI family. The PKIgamma cDNA sequence determined here predicted an open reading frame of 75 amino acids, showing 35% identity to PKIalpha and 30% identity to PKIbeta1. Residues important for the high affinity of PK...

cAMP-dependent protein kinase mediates a variety of cellular responses in most eukaryotic cells. Many of these responses are cytoplasmic, whereas others appear to require nuclear localization of the catalytic subunit. In order to understand further the molecular basis for subcellular localization of the catalytic subunit, the effect of the heat stable protein kinase inhibitor (PKI) was investig...

PKI-402 is a selective, reversible, ATP-competitive, equipotent inhibitor of class I phosphatidylinositol 3-kinases (PI3K), including PI3K-alpha mutants, and mammalian target of rapamycin (mTOR; IC(50) versus PI3K-alpha = 2 nmol/L). PKI-402 inhibited growth of human tumor cell lines derived from breast, brain (glioma), pancreas, and non-small cell lung cancer tissue and suppressed phosphorylati...

We determined whether concurrent blockage of vascular endothelial growth factor (VEGF) receptor and epidermal growth factor (EGF) receptor signaling by two novel tyrosine kinase inhibitors, PTK 787 and PKI 166, respectively, can inhibit angiogenesis and, hence, the growth and metastasis of human pancreatic carcinoma in nude mice. Highly metastatic human pancreatic carcinoma L3.6pl cells were in...

The Public Key Infrastructure (PKI) is a set of hardware, software, people, policies, and procedures needed to create, manage, store, distribute, and revoke digital certificates [18]. PKI systems are today one of the most accepted and used technologies to enable successful implementation of information systems security services such as authentication and confidentiality. Digital forensics is a ...

In this paper, we present an extension of the spi calculus that incorporates primitives for the retrieval of (un)certified public and private keys belonging to users of PKI-based systems. The extended notation also formalises the notion of process ownership by a PKI user. We also define the operational semantics of the new notation and give examples of PKI-based security protocols and review so...

This chapter investigates the problem of secure e-learning and the use cryptography algorithms as tools to ensure integrity, confidentiality, non-reputations, authentication, and access control to provide secure knowledge delivery, secure student feedback, and secure assessments. Providing privacy in e-learning focuses on the protection of personal information of a learner in an e-learning syst...