Securesoureodinfk . unifknlh)
⇒thrift,D→*→ DE Objective
tzn EL di ( x,nxY]< D
min Etddxiz"D >bz
zn.fm
{ ( R,
Re,
D, ,k ) ) achievable ones
.
1211512076
Rate Distortion Theory for Seaney systems : Thursday
K (rate Re )← →
Italy,D→E_Distytyoxnameasurdb
$-23 -
Distortion measured by
ddx ,xT
* *
Let dilxn,xY=÷¥,d:C in ;)
Performance : E[ d. ( X,nxY]{ D,
REngufbaaunmismdeeofwkjenq.amigktddxn.ElHD3DftnFamzyElddXiiZilmDTheoremicbsneotaohieranengi.n.fr.qp.pd.YePYaYx.sjtjg@TfHdisYtetiLykTdzX.x
)]3D<
t.HN#12¥ Gladysatisfied
of ↳ bear this is the cloveHow ?
-(weakly need Raso )
Examp# X~Bern(Yd
Lossless at intended receiver : (17--0)
de Hammingdistance
|
Encoderusing
1 bit of Key told for anyn
.
Let 12=1 bitlsymbd Xorkey
with entire source
RE lnkgtms AKEY
.
MENG.
Etddxielnl )]=42
+ But thissecrecy
1although best we an hope for ) is
veryf-agile because it
Zgets a
tinyside information and
get 1- bit of X"
,then Z
'
knows X "
! ! !
Ingeneral,
construct different random codebook for each key Value
If Rk is big enough , effectively one- time pad
↳Not our case ! !
With LE, consequence is obvious !
It;Ifa±kD*¥nIII¥"I:→
Eavesdropper cares about Pxiln
Causal Disclosure:
ftp.T#pD-inZilmEx" 1 for each i
[HE
extra information .
¥ txiy
→
"
Real - time"
pessimistic assumption .
→ Applies to reputedgo.me
→ Has nice special case
* Solution : Sanitize pastoutput (using secure Dcs )
thmi Rateregion
:
( $, ,Re
,
D, ,Dz ) : F Pura st . Intuition Split description into
×jfu±YxjuY, | two parts .
send U in the dear
Rk3IH,
I ;HU) Secure V,
Pz? Et d. IX. XD
{mzin
E[dz(X,
Hud ]
Nifty : Superposition code :
U is base layer
Vlayer indexed by KY
( dyf for each kg )
€¥°⇐Ei÷iµ"
Ignore U far the moment 4=0 , use secure DCS
Pxnxnlm . ITBIN
Speed case whenyou
have hytoq dist . fnot.
seoeyprkmmmai,EµnEd{x ,;zlm,x"D]Ziayxitj
1nF,
Hlxiln ,xY= 'ah( xnln )
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