CNG Dat

Pace tlo

Vnit

The at of þotding nfornahon by

tAYough he use
Cadt7 So Kat mly hase fas oom the infotnahon is intended
Can ead boc ess it.
Cyahy is atat tenstrucbag and oralyaîng betocal; fhat
þrtuent Rird bartes hublie from eading btvete
Snteonet
Sender
Ms>
-Recveo
s no secuYe because ataceer aty May larTt
data and may m+suse # also
change
Thus to roude secusity and þoteot tAe valuate ino
we use

key
phe key
Sende Rlain decotot Plan Reaeves
+euhmque +echngue
Sane
Symetrie Crgogh

wnyeadette gomead

to
Vice- v6Sa used
algo
 Dat

Paga No.

Tpes

9+ is va SPollest kind g enc«fpthon tecbnlue

ohfch nvelues to

Trfos ahon
Alsoalled Secxet key Coyfptgmahng Piyate
Ex’DES
These oyt fastersond snlex.
sendes have Someho

exchange key in. Secue manneY.

Serder
Reaieves)
Sh artd Seuses Shaved
ostibuhun

Erco fdeergt

Asgonetic’
ond decryphng
Thonyh he kegs ave mathematicaly
leteod and hence
metleving the plain text
by decryhng pher text is feasîbe.
two keys 1.e. þaiy key
huhlie key Anoon to everyane
poivte ey Sndy to
hersen.
Hhat is encyted Sing uthe key
tmly be decvshed usng a ond
AHLeesa
 inhosthe
is key
length erchangng
it
make
yvSgxed ecovered
Paga
io. Poivte
eyHos
t2) wordc
buss secvey
2dPP
kys
Date
Reueve slowes
wit ich for
Most2 ohtext be vsed
Ptckty
CHos+2) to ’
kebository distuibut0r.
Value text
Rela
plais data
bulk
(Hos+)
TheseA
hash lan not
as
ber this is
o key
Encot
ghang
tontent
Use toansf
talelatel
Syianetie
Faster Foy Plem
Mony
Sender
Hoste lain
He
 Dat

Paga Na

Ouarnew Clasical cryftayster

Cyphosgstem is an inblements on
teehnique and Aeir aCLpmpan gung nfoastuchre
to prevsde infornadan Stuiny Strufces .

Seadey
Encha Decgthoy

Encohon Ciphes text Decryton plain

beain
algo. algo tex t

Both 6elong to ymnetie bey coAer

Both methods sed o Convest
ain text ’ cpher text.

The man d r s COn vet

PTblock at a tme hle

Convert fTCT taking
Bloc Stoan
Vses 64 bits uses bts
comlplety Comklek

Tevse encoteo text is

hae
.mode ic Bcs, C&C CAB,6F8
boncþaston ahher
Classical Erchon technfpe
) Subshteh on
Taneosihon
ohch tie teters plan

numbs
text is
oehlacedby othes leter oT

Na me P X

Tenhoshio No reblocement leubsttaton)

technigue we esforn &orne Sost ¢ permuthon
Dn beain text |.e. ord tr Ke symbek
tet
Cos.> NME EAMN

Taanshoshoh Raul fene

Columa
Reyed Reless Ped Doube
Toanstosiho+

4) Manoal7hatChe ubsthefon > ASingle ciphty albhabet fos

each lain text is used
Substhtuhon

N
AE OB N Z

nthis chaacer hlain text

Cbhes textis One to 0ne
 Date

Paga No.

Pelgalysasecie Theze is _no ned Slhsttuhon.

Each OCCuence characher
have a Subsute. loe. we uSe

than ho
Substtuho for same letter.

NP OBX
7
Z

Relathonthe to mang

Toansposihon technfgues > oelaceineat chavaters

we
will eas tange Charactey
basitan
lan tex+ is
douon as sequence
cuagandle and then

all the best lams

To encrt nail fence

debth &
3
a

t t

Cbr ext ALH8S FoRXM 1 T EETO E As

use fos ha essages

’ easy to brtet by atacer
 Page No.

Vigrer her Desgd by Blai_e de

baty alfhatefie Subgittion

The
ercoyphon S done.
dy using 26xas)matiy
MeRod 4 Vignexe Tae ustext to frd eifhex
PI GlVE MONEY
’ LOCK
Key
P’ GlvEMo NEY
K LolcKLOCIkL
Refat tÙe leters key So hat no.
letess in P and K becomes
Now we checde in
Vigcnexe tte the inteseton
P a s kis cþhex text.
alfhabets
ipher teat R wX0 xC POJ

x o x c Po
tfotetetote
checde kos ise

llain text MO NEY

 Pags Na

Metod a2 When Tatle is not given

Encrhon

Decagthon
fT
Key PASCAL
Aey StranIs,0, 8, 2,0,1)
Conyert hey Into integers (As,BA 2925)
S t
P's vaue 889 13
2 11 o
22| i822 |23|18 37 & 13 19 /28-2| 6
S
Text
Convet blain text ’ untegrs
fll key stream unt key strcam lan tet
Add 's value t

Convert mteyer to albhabet.

Cuphertex

add b
uhtoact
(aa-ty
 0ate

Para lo,

JDhe Time Pad

Vezooro C+bhea> text. fox Cncrying alphateti
Simly a tyle of Subsitten Gshtr.
to each chaacter
Z"25)
Lengtk of Length q
lin text

Pr= RAM Sw ARVP K

Rey BABA
RANCHORAM S AR k
See Pr |29 22 20

340 25 20o] 29 I4t8 2o16 /lo

ol 2s 20 314
(Sum> 26,sukr 20)

hhes y IA 2 0 Do sUQK
2
2S 20 2 2o 6o
17 13 2

|2 o

1Ho 1 2 3 22/ D 1 20 s6
S wARDP K
 Paga No.

Hl eishen develefed by lester Hilin 929.

polyatjhabetie cpher
ercays a gou ¢ letlers lallod saygna7h
This method makes Use mathematic_.

To ence C= KPmod s6 Ko Key

ext
P Rlao

Choose keyl Key matiu mubt bea &quare

VIÈw VI 2
22

16 2o &
QUICKNÈSS
LES s

Eag PT’ ATTACK

2 3
then dvmde PT in
L36
CNxi) vectoo
Since lonvert hlain text
uecbor lengti
So

Na encyhon begin
vecto
 Oate

Page No.

C: kP modat
23
omodk
36J
S mgdQs

Contifondng lshebets. K
0ain tot A beeomes
TJ

gd yeco

mgd2s 2 3/
L36 36

Se, Chex Tad FK M PIO

For decnyian) the învesse key motri

2 3
3 6
 Dat

Pars No.

determnant

- (12-9 -3
oleterninaot
Nou, nd mlhjhatue JAvese

KK 1 mad 2bidentihy matrix

So
K 9

Now
ab -b
A then
-c a
22 3 l-s 2 2 tdd
36 J

-3+2< 23
23 2
-3+26 2

Nawy K ady(k)

9 6 23 | sy
22 2 18

K 2 25
| 25
 Pane No.

Nou, we oll dect

Rlain Sext Pa KCmad26

L23

Sm tostya etkes

stechnie
nen- Teaclable tormot
deodng messages fron
’readale fozmat
94 is 8eience of 9ecoverfng the blaln text f the
bcess the
messafe wtkot hauing
Theve ave 1jaous Cofptarabi tack
Cphea texA Grily atak i
atacker Gniy krowk pher tet.
atackes Rnow Borne Combiaahon Ci and
tased on these he tay decry the bitsage.
Chosea Llain tet atack

ohich ossumes tht the attackes an ch00sp andam

lantets do be Crybd and olstain tRe Correshondng
ashe tect. futhe
Ihe goal o atackey is to ais info
tie
shich educes
Scheme.
wast case hisatack lan Bxbose Ke secoet c
nformahon afer Callahng the secret key
Chosen cCihex text atack

attacker can analyze any cißhertest cad get

heir Corrtbjondun g decyston - blatntex+ P
His foal is to acqu secret key
about the attack ed sytesa
fet as
as poss ble.
The ataceey has Capabelet t make the icfm
tack
decryt ang cthertext end send hum
rsults CT 2 he
Thes y analyzng he chesen
aeUeved Pt the intudex
taes t guess tke seoet key

Shudy of codes both crtatng

 Date

Paza tla.

Modes e opeufon >

Electrerl Codebook rnode)>
Simblest moole
blatstext is diyded_nto a mo, of ixed sfze slock.
f messege îs not maliple ef hlock Si2e, fadding
s dene.
tape ene tlock
lece at a time and Cnct
cncoyt it.
Same key used for ehcrpta S9 decnyjton
\et eock Size zS
elan text = Hello everyene
Helo every

elain text ciphes

lock
This wl0 habbenor al the slocbs

bestox Short anount

unt e data Such
mot Seaure for lengthy data
then this made
broduces ane cibher.

ciphcx
block
Decugtho
algo ble
 Date

Page Na.

CBC ’ (Ciþher slock channg Mate)

one
To ovestone Secuny Issue f EcB node
Sokut to the entryhan XoR
Curren+ a, text lock and the
ciþher text teok
preccdng Cncoyst t decryt
Same kyor rhal satoo
vector

encoyphon topheof
lain tlock-s
algo
Cher tlok
eeain blok2

TV
Decoahon
ther Plan
eipher
bloc-I

TV chold be krecon t bo th 6t chould be

Is used In 2nd
caþher
JAus it ts colled
chaining
we use &identcal msg we

TV Cepher wel be Same

 CER" (ciphca feedkk made)
t6is made cipne ven ds fead back to the ner
eyt
block encryfhon Some
bbits
new
feeihaton
A*is an inhal vedor IV
encyhen andRe output bits ae dtyded
and
The kefAaod s- bits aoe &eleted ond Oe
ahed dn XoR esenaton with plan teut bits
The eslt is giveA to ia and
baocess Contnuts
V
Shft Regsta
tbs Sbits
keencyzhas

selec dscad

XOR oits

Decalan ndecryjtoh
bits shit eegeste)
6-s encrHphon
2ey| encyt algo
S bs

sbits P
 Data

Paga No

u) OPB Oudtut Feedtackmode)’

Simslar h Stucure to CFB

Tke outt of caChan un fecd ack

that is feod uck
heneas
CFB the cipher text uni is Ped back

Shft Reustes CIV

fbrs s
key
encal

Decaython P, 2C,at inter chanjed

a Counter equel to lain tex +

hlock sze is useol
Couster s INhaleed to Some alue_ and ten
Incremeoted by 4 oo each Beubsguent blork
Counteo C+!

algo

XoR