a secure and reliable bootstrap architecture.pdf

ASecureandReliableBootstrapArchitecture William ” Universiw ofPennsylvania DistributedSystemsLaboratory Philadelphia, -6389 {waa,fat-her,jms}***@ Abstract putersystem,theintegrityoflo~lerlayersistyp- - prisingthemachine(the lowestlayer)isvalid,integrihofalayercanbeguaran- teedifandonly~:(1)theintegritycrfthelowerlayersis checked,and(2)uronlyuf- plete. Theresulting ii~tegrity“chain”inductivelyguaranteessystemintegrity. Whentheseconditionsarenotmet,a~theytypicallyare notinthebootstrapping(initialization)putersys- tem,nointegri~,theseguar- anteesareincreasinglyimportanttodi~’erseapplications merce,securitysystems,and“works.”Inthispapecwedescribe[heAEGISarchitec- alsoincludesarecoveryproces,~,, andweshowhowthisresultsinrobustsystems. 11Introduction inaseriesoflevelsofabstraction,eachofwhichdefinesa “’virtualmachine”uponwhichhigherlevelsofabstraction thatitisoperatinginanenvironmentwheretheabstractions *Arbatrghisalsowiththe .******@wtment ofDefense. fsnuttr and Fa