All authentication is initially conducted with an internal authentication data store held within ExamSys. The main reasons for using an encrypted local data source are:
Maximise resilience - an exam can continue without interruption even if the connection is lost to the LDAP server.
Network traffic is minimised to the LDAP server especially in large summative exams.
The local authentication can be extended to include uses such as External Examiners who may not have LDAP details.
Every page is initially authenticated locally and only if the data does not match does it do a second LDAP lookup. If the LDAP lookup is successful then the password is stored locally (encrypted).
LDAP configuration settings can be found in the configuration file.
Please see the API page - API, for detailed information on the new API methodology.
Please see the plugin page - plugin_cs_sms.
Please see the IMS page - IMS Enterprise.
The calculation question can either use the inbuilt php maths engine or it can use R. Server setup steps can be found here. ExamSys can be setup to use Rrserve in the configuration screen.