Biomedical subjects

I Mavridis

Publications and source records attributed to I Mavridis.

3 recordsLinked to original sources

PubMed2002

Developing a Public Key Infrastructure for a secure regional e-Health environment.

OBJECTIVES: Internet technologies provide an attractive infrastructure for efficient and low cost communications in regional health information networks. The advantages provided by the Internet come however with a significantly greater element of risk to the confidentiality and integrity of information. This is because the Internet has been designed primarily to optimize information sharing and interoperability, not security. The main objective of this paper is to propose the exploitation of public-key cryptography techniques to provide adequate security to enable secure healthcare Internet applications. METHODS: Public-key cryptography techniques can provide the needed security infrastructure in regional health networks. In the regional health-care security framework presented in this paper, we propose the use of state-of-art Public Key Infrastructure (PKI) technology. Such on e-Health PKI consists of regional certification authorities that are implemented within the central hospitals of each region and provide their services to the rest of the healthcare establishments of the same region. RESULTS: Significant experience in this area has been gained from the implementation of the PKI@AUTH project. CONCLUSIONS: The developed PKI infrastructure already successfully provides its security services to the AHEPA university hospital. The same infrastructure is designed to easily support a number of hospitals participating in a regional health information network.

Computer Security↗

PubMed1978

Expression of functionality of alpha-chymotrypsin. An alternate binding mode in the substrate specificity site.

Three-dimensional 2.8 A resolution x-ray crystallographic studies show that toluenesulfonamide and pipsylamide bind isomorphously in the aromatic specificity binding site of alpha-chymotrypsin. However, their orientation differs by about 90 degrees from that usually associated with substrate-like molecules, suggesting a nonproductive binding mode. A secondary binding site is also operative in one molecule of the dimer of the pipsylamide derivative and it is located some 22 A from the active site; however, this site is not operative in the toluenesulfonamide derivative. Binding of toluenesulfonamide and pipsylamide in the specificity site occurs without inducing any significant changes in the native enzyme structure, in contrast to the behavior observed upon tosylation or upon transition state analogue binding of phenylethaneboronic acid. The structural changes accompanying the formation of the latter derivatives are generally asymmetric with respect to the dimeric structure of alpha-chymotrypsin and are generally confined to the binding domain or cylinder 2 of the enzyme (sequence greater than 122). These changes are displayed in a new way via diagonal distance map representation.

Binding Sites↗

PubMedDate not supplied

Access control based on attribute certificates for medical intranet applications.

BACKGROUND: Clinical information systems frequently use intranet and Internet technologies. However these technologies have emphasized sharing and not security, despite the sensitive and private nature of much health information. Digital certificates (electronic documents which recognize an entity or its attributes) can be used to control access in clinical intranet applications. OBJECTIVES: To outline the need for access control in distributed clinical database systems, to describe the use of digital certificates and security policies, and to propose the architecture for a system using digital certificates, cryptography and security policy to control access to clinical intranet applications. METHODS: We have previously developed a security policy, DIMEDAC (Distributed Medical Database Access Control), which is compatible with emerging public key and privilege management infrastructure. In our implementation approach we propose the use of digital certificates, to be used in conjunction with DIMEDAC. RESULTS: Our proposed access control system consists of two phases: the ways users gain their security credentials; and how these credentials are used to access medical data. Three types of digital certificates are used: identity certificates for authentication; attribute certificates for authorization; and access-rule certificates for propagation of access control policy. Once a user is identified and authenticated, subsequent access decisions are based on a combination of identity and attribute certificates, with access-rule certificates providing the policy framework. CONCLUSIONS: Access control in clinical intranet applications can be successfully and securely managed through the use of digital certificates and the DIMEDAC security policy.

Certification↗