Aa2r큙  0 U`` 0   `pP@0@HH $ @d HHHH̀̀̀ff@  d Footnote TableFootnote**.\t.\t/ - :;,.!?/4 bs9 c0TOCHeading1Heading2   AEquationVariablesF6:,6:-:C:h:;;A;< <$lastpagenum><$monthname> <$daynum>, <$year>"<$monthnum>/<$daynum>/<$shortyear>;<$monthname> <$daynum>, <$year> <$hour>:<$minute00> <$ampm>"<$monthnum>/<$daynum>/<$shortyear><$monthname> <$daynum>, <$year>"<$monthnum>/<$daynum>/<$shortyear> <$fullfilename> <$filename> <$paratext[Title]> <$paratext[Heading1]> <$curpagenum> <$marker1> <$marker2> (Continued)+ (Sheet <$tblsheetnum> of <$tblsheetcount>)Heading & Page <$paratext> on page<$pagenum>Pagepage<$pagenum>See Heading & Page%See <$paratext> on page<$pagenum>. Table All7Table<$paranumonly>, <$paratext>, on page<$pagenum>Table Number & Page'Table<$paranumonly> on page<$pagenum> AAA!!Headings-%HTMLl5y'5|'5555@b1.F4B5.@e2.B a.BÀb.:@':E:G:I:K:M:O:Q:S:U:e':j:lBc.B3.B a.Bb.Bc.:n:p:r:t:v:x:z:::::::::::::::::::::::::::::;;;;; ;";$;&;(;*;C;E;G;I;K;M;O;Q;S;UF6;YCrF8FE;{;};;;;Fg;;;;;;;FV;;;;;;;FG;;;;;CFIFXCFZFiCFkC;;;;;;;;;<< < < <<<<<<<<<=@=B=D=F=H=J=L=N=P=R=T=V=X=Z=\=^=`=b=d=f=h=j=l=n=p=r=tC=x=z=|E,=E>?^?`?b?d?f?h?j?l?n@ @@@@@@@@@@ @"@$@&@(@*@,@.Bd.B6.B a.Bb.Bc.B7.B a.Bb.EB4.B a.Bb.Bc.EEEEEEEEEEEEEEEEE`dqdqdq HmRqHmRHRHR Footnote Hr@qHr@HzHz Single LineHqFootnote 5_  HDq HDHH Double LineHq Double Line5c 5e Hq  Single Line5h HZq  TableFootnote EGxRqEGxREPwEPw TableFootnoted5p HHˆ5xHHˆGe HHˆ5zHHˆl HHˆ5{HHˆW` HHˆ5}HHˆl HUV 5~HUV Wl6Version of   XNovember 25, 1999 10:57 pm V HUV 5HUV l H$ 5H$ WlKNovember 17, 1999 ECS 153 F ALL  1999 Page  W1 U H$ 5H$ l HUV 5HUV Ge HUV 5HUV l H$ 5H$ Ge H$ 5H$ l HHˆ5HHˆU(%% `Notes for November 17, 1999 `Greetings and Felicitations!  `Puzzle of the Day `Privilege in OSes `ENone (original IBM OS; protect with password, or anyone can read it) `-Fence, base and bounds registers; relocation `Tagged architectures O`NMemory management based schemes: segmentation, paging, and paged segmentation X`"Different forms of access control Y` UNIX method Z`"ACLs: describe, revocation issue [`MULTICS rings  `MULTICS ring mechanism  `CMULTICS rings: used for both data and procedures; rights are REWA * 5 ( b 1 ,  b 2 ) access bracket - can access freely; ( b 3 ,  b 4 ) call bracket - can call segment through gate; so if  a s UUlaccess bracket is (32,35) and its call bracket is (36,39), then  assuming permission mode (REWA) allows access , a procedure in: "Crings 0-31: can access  a , but ring-crossing fault occurs Capability-based addressing: show picture of accessing object R`JShow process limiting access by not inheriting all parents capabilities S`-Revocation: use of a global descriptor table T` Lock and Key U nAssociate with each object a lock; associate with each process that has access to object a key (its a cross @between ACLs and C-Lists) V Example: use crypto (Gifford).  X  object enciphered with key  K . Associate an opener  R  with  X . Then: *|OR-Access:  K  can be recovered with any  D i  in a list of  n  deciphering transformations, so U.H R  = ( E 1 ( K ),  E 2 ( K ), ...,  E n ( K )) and any process with access to any of the  D i s can access the file B@$AND-Access: need all  n  deciphering functions to get  K :  R  =  E 1 ( E 2 (... E n ( K )...)) HHˆ5HHˆld:>!! $$:?$$"B!G Bm Z $$:A$$ l} :D%  G eHeadings Table } :F  G e } :H  G e }l:J"&l G eHeading Level }:L%' G eParagraph Format }:N&( G e Comments }l:P')l G e2 }:R(* G e Heading1 }:T)O G e d:c-- $$:d+$$V- =:7^bf~zvrnjUX[IMQ.14FC@=:7GBm ` _ ^ ] \ [ $$:f+$$%,, l}$ :i#T1$ $W eCharacter Macros }l :k#l $W e } :m# $W e }$$H:o#.2$$H$W  e Character }l$:q#13l$$W!  e Replace With }$:s#24$$W"  e Comments }$4H:u#35$4H$W#  e }l4:w#46l4$W$  e¢ }4:y#5F4$W%  e }$”H:#<8$”H$W&  e }l”:#79l”$W'  e... }”:#8”$W(  e }$„H:#?;$„H$W)  e }l„:#:<l„$W*  e- }„:#;7„$W+  e }$tH:#B>$tH$ W,  e }lt:#=?lt$ W-  e-- }t:#>:t$ W.  e }$dH:#EA$dH$ W/  e }ld:#@Bld$ W0  e° }d:#A=d$ W1  e }$TH:#HD$TH$ W2  e }lT:#CElT$ W3  e® }T:#D@T$ W4  e }$DH:#6G$DH$ W5  e }lD:#FHlD$ W6  e© }D:#GCD$ W7  e }$ :#]M$ $ W8 eGeneral Macros } :# $ W9 e } :# $ W: e }\ :#\ $ W; e }$h:#IN$h$W<  e Macro Name }h:#MOh$W=  e Replace With }h:#NPh$W>  eHead }\:#OQ\$W?  e Comments }$h:#PR$h$W@  e }h:#QSh$WA  e }h:#RTh$WB  e }\;#S.\$WC  e }$ ;#mX$ $ WD eCross-Reference Macros } ;# $ WE e }D ;#D $ WF e }$;#UY$$ WG  e Macro Name };!#XZ$ WH  e Replace With }D;##Y[D$ WI  e Comments }$;%#Z\$$ WJ  e See Also };'#[]$ WK  eSee <$paratext> }D;)#\ID$ WL  e }$Z ;B#9b$Z $ WM eSystem Macros }Z ;D#Z $ WN e }Z ;F#Z $ WO e }\Z ;H#\Z $ WP e }$jh;J#^c$jh$ WQ  e Macro Name }jh;L#bdjh$ WR  e Replace With }jh;N#cejh$ WS  eHead }\jh;P#df\jh$ WT  e Comments }$zh:;R#eg$zh:$ WU  e StartOfDoc }zh:;T#fhzh:$ WV  e }zh:;V#gizh::$ Y 4e ����e <$defaulttitle> W����e AZe }\zh:;X#h\zh:$ WX  e }$h;z#qk$h$ W\  eEndOfLastSubDoc }h;|#jlh$ W]  e }h;~#kmh$ W^  e }\h;#lU\h$ W_  e }$Xh:;#uo$Xh:$ W`  eStartOfLastSubDoc }Xh:;#npXh:$ Wa  e }Xh:;#oqXh::$ ~ 4e b����e <$defaulttitle> }����e Ae }\Xh:;#pj\Xh:$ Wc  e }$Hh;#ys$Hh$ Wd  eEndOfFirstSubDoc }Hh;#rtHh$ We  e }Hh;#suHh$ Wf  e }\Hh;#tn\Hh$ Wg  e }$h:;#}w$h:$ Wh  eStartOfFirstSubDoc }h:;#vxh:$ Wi  e }h:;#wyh::$ { 4e j����e <$defaulttitle> z����e A|e }\h:;#xr\h:$ Wk  e }$h;#{$h$ Wl  e EndOfSubDoc }h;#z|h$ Wm  e }h;#{}h$ Wn  e }\h;#|v\h$ Wo  e }$h:;#$h:$ Wp  eStartOfSubDoc }h:;#~h:$ Wq  e }h:;#h::$ x 4e [����e <$defaulttitle> r����e Aye }\h:;#z\h:$ Ws  e }$h;#i$h$ Wt  e EndOfDoc }h;#h$ Wu  e }h;#h$ Wv  e }\h;#~\h$ Ww  e } ;#  $ G eHTML Options Table } ;# $ G e } ;# $ G e };# $ G eControl };# $ G eValue }H;# H$ G e Comments };# $ G e Image Format };# $ g % 0001IMAGGIF E MACP0001GIF }H;# =H$ G e } <+ , G eHTML Mapping Table } <+ , G e } < + , G e } < + , G e } <+ , G e }.<+., !G eFrameMaker Source Item }~<+~, !G e HTML Item }6<+6, !G e }6.<+6., !g %Include EAuto# }.<+., !G e Comments }<+, "G e }H<+H, "G eElement }6<+6, "g %New Web EPage? }6< +6, "G e }<"+, "G e }<$+, #G eP:Body }H<&+ H, #G eP }6<(+!6, #G eN }6<*+ "6, #G eN }<,+!2, #G e d<.%% $$6, 'G. eX:Page }H<{+57H, 'G/ e See Also }6<}+686, 'G0 eN }6<+796, 'G1 eN }<+80, 'G2 e }<+C;, (G3 eX:Heading & Page }H<+:<H, (G4 e See Also }6<+;=6, (G5 eN }6<+<>6, (G6 eN }<+=5, (G7 e }<+H@, )G8 eC:EquationVariables }H<+?AH, )G9 eEM }6<+@B6, )G: eN }6<+AC6, )G; eN }<+B:, )G< e }<+ME, *G= e C:Emphasis }H<+DFH, *G> eEM }6<+EG6, *G? eN }6<+FH6, *G@ eN }<+G?, *GA e }<+RJ, +GB eP:Title }H<+IKH, +GC eH* }6<+JL6, +GD eN }6<+KM6, +GE eN }<+LD, +GF e },<+WO,, ,GG e P:TableTitle }H,<+NPH,,, ,3 eLI He Parent = OL A0e Depth = 0 }6,<+OQ6,, ,GI eN }6,<+PR6,, ,GJ eN },<+QI,, ,GK e }<+\T, -GL eP:TableFootnote }H<+SUH, -GM eP }6<+TV6, -GN eN }6<+UW6, -GO eN }<+VN, -GP e }<+aY, .GQ eP:Rule }H<+XZH, .GR eP }6<+Y[6, .GS eN }6<+Z\6, .GT eN }<+[S, .GU e }<+f^, /GV e P:Numbered1 }H<+]_H, /GW eH* }6<+^`6, /GX eN }6<+_a6, /GY eN }<+`X, /GZ e }<+kc, 0G[ e P:Numbered }H<+bdH, 0G\ eH* }6<+ce6, 0G] eN }6<+df6, 0G^ eN }<+e], 0G_ e }<+ph, 1G` eP:Mapping Table Title }H<+giH, 1Ga eP }6<+hj6, 1Gb eN }6<+ik6, 1Gc eN }<+jb, 1Gd e }<+um, 2Ge eP:Mapping Table Cell }H<+lnH, 2Gf eP }6<+mo6, 2Gg eN }6<+np6, 2Gh eN }<+og, 2Gi e }<+zr, 3Gj eP:ManHeading2 }H<+qsH, 3Gk eP }6<+rt6, 3Gl eN }6<+su6, 3Gm eN }<+tl, 3Gn e }<+w, 4Go e P:ManHeading }H<+vxH, 4Gp eP }6<+wy6, 4Gq eN }6=+xz6, 4Gr eN }=+yq, 4Gs e }=+|, 5Gt e P:ManBody }H=+{}H, 5Gu eP }6= +|~6, 5Gv eN }6= +}6, 5Gw eN }= +~v, 5Gx e }=+ , 6Gy e P:LetteredA }H=+H, 6Gz eH* }6=+6, 6G{ eN }6=+6, 6G| eN }=+{, 6G} e }=+, 7G~ e P:Lettered }H=+H, 7G eH* }6=+6, 7G eN }6=+ 6, 7G eN }=!+, 7G e }=#+ , 8G e P:Indented }H=%+ H, 8G eP }6='+ 6, 8G eN }6=)+ 6, 8G eN }=++ , 8G e }=-+, 9G eP:HeadingRunIn }H=/+H, 9G eP }6=1+6, 9G eN }6=3+6, 9G eN }=5+ , 9G e }=7+, :G e P:Heading2 }H=9+H, :G eH* }6=;+6, :G eN }6==+6, :G eN }=?+, :G e }=A+", ;G e P:Heading1 }H=C+H, ;G eH* }6=E+6, ;G eN }6=G+6, ;G eN }=I+, ;G e }=K+', <G eP:Heading Info }H=M+ H, <G eP }6=O+!6, <G eN }6=Q+ "6, <G eN }=S+!, <G e }=U+,$, =G e P:Footnote }H=W+#%H, =G eP }6=Y+$&6, =G eN }6=[+%'6, =G eN }=]+&, =G e }=_+1), >G! eP:CellHeading }H=a+(*H, >G" eP }6=c+)+6, >G# eN }6=e+*,6, >G$ eN }=g++#, >G% e }=i+6., ?G& e P:CellBody }H=k+-/H, ?G' eP }6=m+.06, ?G( eN }6=o+/16, ?G) eN }=q+0(, ?G* e },=s+"3,, @G+ e P:Bulleted }H,=u+24H,,, @1 eLI e Parent = UL A,e Depth = 0 }6,=w+356,, @G- eN }6,=y+466,, @G. eN },={+5-,, @G/ e }$D?]#<8$D$ AW4  eCSS Export Encoding }D?_#79D$ AW5  e ISO-8859-1 }hDH?a#8^hDH$ AW6  e }?c#?;$ BG7 eExport Encoding }?e#:<$ BG8 e ISO-8859-1 }H?g#;7H$ BG9 e }?i#>$ CG: e!Copy Files Imported by Reference }?k#=?$ CG; eN }H?m#>:H$ CG< e }l@ EAl DG= e1 }@ @B DG> eTitle }@A DG? e }l@HDl EG@ e4 }@CE EGAe Numbered1 }@D@ EGB e }l@KGl FGC e4 }@FH FGDe Numbered }@GC FGE e }l@NJl GGF e5 }@IK GGGe LetteredA }@!JF GGH e }l@#QMl HGI e5 }@%LN HGJe Lettered }@'MI HGK e }l@)*Pl IGL e3 }@+OQ IGM e Heading2 }@-PL IGN e }E+[S, JG2 e C:Subscript }HE+RTH, JGW eEM }6E+SU6, JG\ eN }6E+TV6, JG] eN }E+U, JG^ e },E+`X,, KG_ e P:Romanedi }H,E+WYH,,, K` eLI ke Parent = OL Ale Depth = 0 }6,E+XZ6,, KGa eN }6,E+Y[6,, KGb eN },E+ZR,, KGc e },E+*],, LGd e P:Romaned }H,E+\^H,,, Le eLI ie Parent = OL Aje Depth = 0 }6,E+]_6,, LGf eN }6,E+^`6,, LGg eN },E+_W,, LGh e dLeftdRightd ReferenceddHeadingsd+HTMLd#HTML f@PB TitleBody. f@NE B Numbered1 N:.Numbered. f@N B Numbered N:.\t. f@N B Numbered N:.\t. f@ B Footnote. f@NE B Numbered1 N:.Numbered. f@T BHeading2Body. f@T B HeadingRunInBody. f@ B Indented. @@ B Body. $f@AE B$. LetteredA A:.Lettered. f@ B TableFootnote. f@T B TableTitleT:Table : . @@ BHeader Double Line. f@T B TableTitleT:Table : . @@ B Mapping Table Title. $f@A B$. Lettered A:.\t. f@ B CellFooting. $f@AE B$. LetteredA A:.Lettered. $f@A B$. Lettered A:.\t. @@ BFooter. @@ BMapping Table Cell. @@BMapping Table Title. f@ BRule. @@ B Mapping Table Cell. @@ B Mapping Table Cell. @@ BMapping Table Cell. @@ B $ H l      D h  ManHeading. @@BMapping Table Cell. 6$f@R B6. RomanedR:.. 6$f@R B6. Romanedi R:.. f@ B CellHeading. f@ BBody.  f@P B Heading InfoBody. f@ BBody. f@ B CellHeading. f@ B Bulleted\t. f@ BCellBody. f@ BCellBody.  f@PBTitleBody.  @@ B ManHeading2.  f@T BHeading1Body. @@ B $ H l      D h  ManBody. BEmphasisBEquationVariables B B B B B 33BB 33B B B B B B Subscript B Subscript B Subscript B BThinMediumDoubleThick@ Very Thin H&5H&5H&5H&5H&5Format A H&5H&5H&5H&5H&5Format BH Mapping TableH Mapping Table vDl h pH   h h h     ( h h h h  N A H >€ J H 6 6 L  "#$ %&'I ()*$ $./0$$h$123$4h $456$”h$789$„h $:;<$th $= > ? $dh $@ A B $Th $C D E $Dh $F G H $ $I J K L $ $MNOP$$QRST$ $UVW$$XYZ$$[\]$Z $^_`a$j$bcde$z:$fghi$$jklm$X:$nopq$H$rstu$:$vwxy$$z{|}$:$~$$ $$   C$   !,      ",!!!!!!#,""""""@,## #!#"#%L,&$'$($)$*$&$,+%,%-%.%/%'%,0&1&2&3&4&(&,5'6'7'8'9')',:(;(<(=(>(*(,?)@)A)B)C)+),D*E*F*G*H*,*,I+J+K+L+M+,-+,N,O,P,Q,R,.,,S-T-U-V-W-/-,X.Y.Z.[.\.0.,]/^/_/`/a/1/,b0c0d0e0f020,g1h1i1j1k131,l2m2n2o2p242,q3r3s3t3u353,v4w4x4y4z464,{5|5}5~5575,6666686,7777 797, 8 8 8 88:8,99999;9,:::::<:,;;;;;=;,<< <!<"<><,#=$=%=&='=?=,(>)>*>+>,>@>,-?.?/?0?1?,#?,2@3@4@5@6@$DB$7A8A9ACA$:B;BC?CE @DADBDFD CEDEEEGE FFGFHFHF IGJGKGIG LHMHNHH OIPIQIK,RJSJTJUJVJ,LJ,WKXKYKZK[K,$K,\L]L^L_L`LComment6:+d BlackT!WhiteddARedddGreendd BluedCyandMagentad YellowHeader/Footer $1Header/Footer $1Header/Footer $2Header/Footer $2IndexIndexCommentCommentSubjectSubjectAuthorAuthorGlossaryGlossaryEquationEquation Hypertext Hypertext  Cross-Ref Cross-Ref Conditional TextConditional TextPositionFMPrivatePositionFMPrivateRangeEndFMPrivateRangeEndFMPrivate HTML Macro HTML Macro M.Times.B Times-Bold FrameRoman M.Times.P Times-Roman FrameRoman M.Times.BITimes-BoldItalic FrameRoman M.Helvetica.BHelvetica-Bold FrameRoman M.Times.I Times-Italic FrameRomanO HelveticaATimes#Regular#RomanBoldRegularItalic6̖ZB/?vSUTa3@ 1k<.rbPEcZzq>'zcϯ9A-^ j\:5CuJh䈑g$-8BIЊLJ\Y|-