AaTr}  0 P`Pp P`@```0pHH $ @d HHHH̀̀̀ff@  d Footnote TableFootnote**.\t.\t/ - :;,.!? - a; dxTOCHeading1Heading2   bEquationVariablesIt?@>@@A A#A@??? <$lastpagenum><$monthname> <$daynum>, <$year>"<$monthnum>/<$daynum>/<$shortyear>J<$hour>:<$minute00> <$ampm> on <$dayname>, <$monthname> <$daynum>, <$year>"<$monthnum>/<$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> Handout DateJanuary 7, 1999Heading <$paratext>AHTMLHeadings2A;;==??Ac5y??? 5 5*C1.C4.?*???"?$?& ?( ?* ?, ?. ?0 ?2 ?4 ?6 ?8 ?: ?< ?> ?@ ?B ?D ?F ?H ?J ?L ?N ?P ?R ?T ?V Ca.>+C2.?X ?Z ?\ ?^ ?` ?b E E ?f ?h ?j ?l ?n ?p ?r ?t ?v ?x F F ?| ?~ ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? FV FX ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? F F ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? F F ? ? ? @ @ @ @ @ @  @  @ @ @ @ @ @ @ @ @ @  @" @$ ABADAFAH AJ AL AN APAR AT@& @( @* @, @. @0 @2 @4 @6 @8 @: @< @> @@ @B @D @F @H @J @L @N @P @R @T @V @X @Z @\ @^ @` @b @d @f @h @j @l @n @p @r @t @v @x @z @| Ca.@~ @ @ @@Cb.Cc.C5.@@ @ @ @ AVAX AZ@ @ @ @ @ A\A^ @ @ @ @ @ @ @ @ @ @@@@ @ @ @ @ @ @ @ @ @ @ @ @ @ @ HAe@ @ @ @ @ @ @ @ @ @ @ @ G G G @@@@ @ @ @ A A EE E  A AAAA A A A A A A  A" A%A'A)A+ A- A/ A1 A3 A5 A6Ca.Cb.Cc.Cd.Ce.Cg.C6.C7.Ca.Cb.C8.Ca.Cb.C 9.C a.C b.C c.C d.C e.C f.C3.C Ca.Cb.Cc.Cd.C+CCCCCCCCCCCCCCCDDDDDDDDDD D D D D DDDDDDD a.D!b.D"c.D#D$D%D\f.D D D D D D D D D D D D D D D D D D E  E  E E E E E G G G G G G G G G G G G G G G G G G G G G G G G G G G G G G G G H H H H H  H  H  H H H H H H@ HB HT HV Hh Hj H H H H H H rdqdD22d? HmR? HmRHRHRFootnote Hr@? Hr@HzHz Single LineH? Footnote ?   HD?  HDHH Double LineH? Double Line? ? H?  Single Line? HZ?  TableFootnote EGxR?EGxREPwEPw TableFootnoted5p HHˆ5xHHˆGe HHˆ5zHHˆld?d?dHl d?d))wrmhc^^adgjmp vy| #'+/ADROL963W3@m       }d ?!d WeHTML Mapping Table }Hd ?Hd We }Hd ?Hd We HUV 5HUV Ge HUV 5HUV l H$ 5H$ Ge H$ 5H$ l HHˆ5HHˆ''( `Outline for May 11, 2000 `Greetings and felicitations! '`Worm in restricted area )D`Confinement problem rP`Legitimate channels s`Storage channels t`Covert channels Hv`Covert channels J`/What are they; note probabilistic distribution K`"Storage vs. timing; give examples L`Resource matrix M`Formal methods `Information flow L`-Deals with right to disseminate information. R`SAssume lattice-structured information flow policy ( la BLP); represent as (SC, ) S`(Explicit vs. implicit information flows T檛`)Program statements; define when secure 4` assignment 5` compound 6` alternation 7` iteration 8`function call !x lgoto; control flow graph and immediate forward dominator (first block that lies on all paths from the block @"under consideration and the exit) 9`.composition of above; show compile/parse tree :T`Give examples (copy) ;`#Execution-Based with Fixed Classes `&Execution-Based with Variable Classes ?`&Change variables class to allow flow @`Fails for implicit A`Compiler-Based Mechanisms B`+assures secure execution of each statement C`+may reject secure mechanisms (not precise) D` procedures E`arrays F`gotos (blocks) AG`errors HHˆ5HHˆ2l}Hd ?!Hd W e }Hd ?#Hd W e }H&?%"H&% FrameMaker PE Source Item }H ?'!$H We HTML Item }H ?)H We }H&?+"%H& WeInclude Auto# } H&?-$' H& We Comments }H?/H We }HH?1%(HH WeElement }H?3'+H%New Web PEPage? }H?5H We } H?7 H We }H ?9(,H We P:Date Line }HH ?;+-HH WeP }H ?=,.H WeN }H ??-/H WeN } H ?A.0 H We }EH ?C/1EH We P:Reading }HEH ?E02HEH WeP }EH ?G13EH WeN }EH ?I24EH W eN } EH ?K35 EH W!e }QH ?M46QH W"eP:Title }HQH ?O57HQH W#eH* }QH ?Q68QH W$eN }QH ?S79QH W%eN } QH ?U8: QH W&e }]H ?W9;]H W*eP:Body }H]H ?Y:<H]H W+eP }]H ?[;=]H W,eN }]H ?]<>]H W-eN } ]H ?_=? ]H W.e }iH(?a>@iH( W/e P:Numbered1 }HiH(?c?AHiH((2eLI 0e Parent = OL Q1e Depth = 0 }iH(?g@BiH( W3eN }iH(?iACiH( W4eY } iH(?kBD iH( W5e }H ?mCEH  W6e P:Heading1 }HH ?oDFHH  W7eH* }H ?qEGH  W8eN }H ?sFHH  W9eN } H ?uGI H  W:e }H(?wHJH(  W;e P:Numbered }HH(?yIKHH(( >eP <e Parent = OL Q=e Depth = 0 }H(?}JLH(  W?eN }H(?KMH(  W@eY } H(?LN H(  WAe }H ?MOH  WBe P:CellBody }HH ?NPHH  WCeP }H ?OQH  WDeN }H ?PRH  WEeN } H ?QS H  WFe }H ?RTH  WGeP:CellHeading }HH ?SUHH  WHeP }H ?TVH  WIeN }H ?UWH  WJeN } H ?VX H  WKe }H ?WYH  WLe P:Footnote }HH ?XZHH  WMeP }H ?Y[H  WNeN }H ?Z\H  WOeN } H ?[] H  WPe }H(?\^H( WQe P:Bulleted }HH(?]_HH((TeLI Re Parent = UL QSe Depth = 0 }H(?^`H( WUeN }H(?_aH( WVeN } H(?`b H( WWe }H ?acH WXe P:Heading2 }HH ?bdHH WYeH* }H ?ceH WZeN }H ?dfH W[eN } H ?eg H W\e }H?fhH]% P:HeadingRuPEnIn }HH?giHH W^eP }H?hjH W_eN }H?ikH W`eN } H?jl H Wae }7H ?km7H Wbe P:Indented }H7H ?lnH7H WceP }7H ?mo7H WdeN }7H ?np7H WeeN } 7H ?oq 7H Wfe }CH?prCHg% P:TableFootPEnote }HCH?qsHCH WheP }CH?rtCH WieN }CH?suCH WjeN } CH?tv CH Wke }]H(?uw]H( Wle P:TableTitle }H]H(?vxH]H((oeLI me Parent = OL Qne Depth = 0 }]H(?wy]H( WpeN }]H(?xz]H( WqeN } ]H(?y{ ]H( Wre }H ?z|H Wse P:BodySpaced }HH ?{}HH WteP }H ?|~H WueN }H ?}H WveN } H ?~ H Wwe }H ?H WxeP:Date }HH ?HH WyeP }H ?H WzeN }H ?H W{eN } H ? H W|e }H(?H(}% P:NumberedPESpaced }HH(?HH((eP ~e Parent = OL Qe Depth = 0 }H(?H( WeN }H(? H( WeY } H(? H( We }H @ H WeP:DateProject }HH @ HH WeP }H @ H WeN dA=dA> dl dA? diYWBm  }d AA d !WeHeadings Table }Hd AC Hd !We }Hd AE Hd !We }HAG H "WeHeading Level }HHAI HH"%Paragraph ForPEmat }HAK H "We Comments }HAM H#W e2 }HHAO HH #We Heading1 }HAQ OH #We }H @ H WeN } H @  H We }H @ H W e C:BoldItalic }HH @ HH W eSTRONG }H @H W eN }H @H W eN } H @ H W e }H@!H% C:EquationPE Variables }HH@ "HH WeEM }H@!#H WeN }H@"$H WeN } H@#% H We }H @$&H We C:Italic }HH @!%'HH WeEM }H @#&(H WeN }H @%')H W eN } H @'(* H W!e }H @))+H W"eC:Bold }HH @+*,HH W#eSTRONG }H @-+-H W$eN }H @/,.H W%eN } H @1-/ H W&e }H@3.0H'% X:Heading & PEPage }HH@5/1HH W(e See Also }H@702H W)eN }H@913H W*eN } H@;24 H W+e })H @=35)H W,eX:Page }H)H @?46H)H W-e See Also })H @A57)H W.eN })H @C68)H W/eN } )H @E79 )H W0e }5H@G8:5H1% X:See HeadPE ing & Page }H5H@I9;H5H W2e See Also }5H@K:<5H W3eN }5H@M;=5H W4eN } 5H@O<> 5H W5e }OH @Q=?OH W6e X:Table All }HOH @S>@HOH W7e See Also }OH @U?AOH W8eN }OH @W@BOH W9eN } OH @YAC OH W:e }[H@[BD[H ;% X:Table NumPE ber & Page }H[H@]CEH[H  W<e See Also }[H@_DF[H  W=eN }[H@aEG[H  W>eN } [H@cFH [H  W?e }uH@eGJuH $W@e X:Heading HHˆDHHˆd))2N 8Examples of Compiler-Based Information Flow Enforcement $@ Mechanisms OB`Here are some examples. P![`copy2 Qn`Wprocedure   copy2 ( x :  integer class  { x }; R{`F var  y :  integer class  { x }); S`#copy  x  to  y  T`? var  z :  integer class  { x }); U`  begin V`0 z  := 1; Low   z W`1 y  := -1; Low   y X`W while   z  = 1  do z   y     z Y`  begin Z`< y  :=  y  + 1; y   y [`9 if   y  = 0 y   z \`F then   z  :=  x  x   z ]`> else   z  := 0 Low   z ^`  end _`  end ``end   copy2 . a!J`copy2  with goto b]`Wprocedure   copy2 ( x :  integer class  { x }; cj`F var  y :  integer class  { x }); d`#copy  x  to  y  e`? var  z :  integer class  { x }); f`  begin g30`(1: z  := 1; b 1 h3/` y  := -1; i303/`J2: if   z  1  then goto  6; b 2 jf_`63: y  :=  y  + 1; b 3 k`5 if   y  0  then goto  5; l30晏`(4: z  := x; b 4 m̿` goto  2; n30̿`(5: z  := 0; b 5 o` goto  2;  p` 6: end q`end   copy2 . I7` u*C`&IFD( b 1 ) =  b 2 vQ`&IFD( b 2 ) =  b 6 Aw`XIFD( b 3 ) = IFD( b 4 ) = IFD( b 5 ) =  b 6 }HuH@gHKHuH$A% USE XREF PEFMT }uH@iJLuH $WBeN }uH@kKMuH $WCeN } uH@mLN uH $WDe }H@oMRH %WEe P:Header }KH AS PKH 0We3 }HKH AU OQHKH 0WZe Heading2 }KH AW PWKH 0W[e }HH@qNSHH%F%THROW PEAWAY }H@sRTH %WGeN }H@uSUH %WHeN } H@wTV H %WIe }©H @yUZ©H &WJe P:computer }WHAY QXWH 2W\e1 }HWHA[ WYHWH2Wb eTitle }WHA] XWH 2Wce }H©H @{V[H©H &WKeP }©H @}Z\©H &WMeN }©H @[]©H &WNeN } ©H @\ ©H &WOe }»d @G]a»d I'WPeHTML Options Table }D»d @GD»d I'WQe }D»d @GD»d I'WUe }D @G^bD I(WVeControl }DH @GacDH I(WWeValue }H @GbdH I(WXe Comments }D6@GceD6 I)WYe Image Format }DH6@GdfDH66I)]% 0001IMAGGIF p MACP0001GIEF }H6@GegH6 I)W^e }D @GfhD I*W_eBanners }DH @GgiDH I*W`eN }H @GhjH I*Wae }D@GikDI+e% Banner ReferPE ence Frame }DH@GjlDH I+Wfe }H@GkmH I+Wge }D(@GlnD((I,h$% Copy Files  Imported by PE Rerefernce }DH(@GmoDH( I,Wie }H(@GnpH( I,Wje }DD(@GoqDD((I-k% Copy Files  Imported by PE Reference }DDH(@GprDDH( I-WleN }DH(@Gq DH( I-Wme }Vd @G yVd I.WneSystem Macros }?Vd @G?Vd I.Woe }Vd @GVd I.Wpe }f? @Gvzf? 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AW"e Macro Name }?xH A')?xH AW#e Replace With }xH A(*xH AW$eHead }xH A)+xH AW%e Comments }? A*,? BW&e }?H A+-?H BW'e }H A,.H BW(e }H A!-/H BW)e }d A$.Ad CW*eCharacter Macros }?d A&?d CW+e }d A(d CW,e HHˆDHHˆIIl}? D84? FWye }?H D35?H FWze... }H D4H FW{e }? DK7? GW|e }?H D68?H GW}e- }H D73H GW~e }? DNJ? HWe d>;?H$ >:=H$ << l H$ >:H$ ;W l4May 11, 2000ECS 253 Spring 2000Page  1  HUV >:;?HUV >> l HUV >:HUV =W l?Last modified at  10:18 pm on Thursday, May 11, 2000  HHˆ>:=HHˆ@@ l HHˆ>:HHˆ?W ` }? A*/B? DW-e Character }?H A,AC?H DW.e Replace With }H A.BDH DW/e Comments }? A0CE? EW0e }?H A2DF?H EW1e¢ }H A4ERH EW2e dA8HHdA9GdII l dA:Gd  wHwrmhc^^adgjmp vy|  #'+/ADROL963}?H D9K?H HWe-- }H DJ6H HWe }? DQM? IWe }?H DLN?H IWe° }H DM9H IWe }? DTP? JWe }?H DOQ?H JWe® }H DPLH JWe }? DFS? 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