CCTOS: Network Security

Draft Version 6.5, 10 May 2011, Etienne Saliez, ---- Next - Previous - Index of CCTOS Issues, /

Issues:
- Security:
  - Security is a major concern for confidentiality, but above all for the reliability of the applications. Indeed orders for treatments need to be safely transmitted.
  - Security require attention at both sides of the communication, server and client. A problem is that it is relatively difficult to control the security at the client side. For example passwords should not be saved.
  - Remark: the possible goal is only a high degree of security, higher than what was possible with papers and manual signatures.
- Reliability:
  - Integrity of the information.
- Data availability:
  - Medical emergencies can arise at any time 24 hours a day, and access to the patient record could be important.
  - Telecommunications could be interrupted at any time for some time up to several hour or a few days, particularly in developing regions.
  - Any machine could fail at any time.
Approaches:
- All communications must be encrypted. Current technologies are based on HTTPS.
- In principle only a minimum of information should go through the communication channel.
  - Identification of the user session, by means of a kind of cookies, moreover very temporary and if possible somehow encrypted.
  - Of course the requested data to be displayed and new input as which button has been pressed and new input data.
- Communications must be encrypted. Moreover the traffic on the line should be limited to what is really essential, i.e. identification of the client (maybe a kind cookie) and what is new. For security reasons, systems based on steering information in long URLs should be avoided.
- Sensitive information should not unnecessary depend on slow and potentially unreliable telecommunications between server and workstation. Session information should be maintained at the server side.
- Checksums or signatures should be included in critical information.
- Automated backup must be foreseen, not depending on the attention of local users:
  - Backup on several devices.
  - Incremental backups.
  - In situations where communication are very difficult, it could even be considered to keep backup at the workstation level, regarding the most critical information for the surrounding patients.