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Dynamic Sessions. Assumptions. Builds on Browser Binding Sessions Security related Limit Assertion validity Central Session Authority Maintains global sessions Participant Sites Maintain local sessions. Requirements. User experiences seamless distributed session Session operations
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Assumptions • Builds on Browser Binding • Sessions • Security related • Limit Assertion validity • Central Session Authority • Maintains global sessions • Participant Sites • Maintain local sessions
Requirements • User experiences seamless distributed session • Session operations • Session Start • User signoff • Admin signoff • Idle timeout – single global timeout interval • Participant sites choose level of participation • Session start only • Ignore timeout • Full
Session Start • Prior Authentication • Browser contacts PS • PS obtains Session Assertion from SA • SA records PS for this session • PS implements local session Browser Participant Site Session Authority
User or Admin Signoff • User or Admin requests signoff • Session Authority informs PSs • One way or Req/Resp • PS query alternative Participant Sites Browser Session Authority
Session Idle Timeout • Two phases • Discovery • Signoff – same as in previous • Participant Options • Synchronized local session • Shorter local session timeout • Longer local session timeout
PS Timeout Options • Longer local timeout • Ignore signoff message • Timeout based on local touch • Potentially inconsistent user experience • Shorter local timeout • Local session ends • User returns – appears to PS same as new user • Contacts SA – global session still in progress • Local session reestablished
Timeout Discovery Option 1 • SA sets session touch time at each session start • PSs report all recent touches to SA at fixed interval • SA calculates timeout Participant Sites Session Authority
Timeout Discovery Option 2 • SA sets session touch time at each session start • When session touch exceeds timeout, SA queries all PSs not reported recently • PSs report all recent touch times – all sessions Participant Sites Session Authority
Comparison • State maintained same • PSs - touch times all sessions • SA – per session - most recent touch & PS list, last report time per PS • Option 1 simpler algorithm for SA • Option 2 much less net traffic under any reasonable assumptions about # of PSs, users and PSs per user