Course :- Cryptology

[Shaim]

Re: Course :- Cryptology

walikum as salam
itna bi muskil naeen hay , zara ghor sey paro

Assalam-o-Alikum
nahii buhaat mushkil hai main fail ho gai

[Shaim]

Re: Course :- Cryptology

common ciphers:-

1. ceaser cipher:-
yeh nihayat simple cipher tha.
is ki mathematical equation hay

y=(x+3) mod 26

lets take an example
in cryptography we assign the values with the alphabets

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 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25

her character key nechay us ki value likhi hay

ab misal key tur per
plain text hay hamara

PT : ME HERE

y1=(M +3) mod 26 =(12+3) mod 26 = 15 mod 26 =15=P
y2=(E+3) mod 26 =(4+3) mod 26 =7mod 26 =7=H
y3= (H +3) mod 26=(7+3)mod 26=10mod 26 =10=K
y4=(E+3) mod 26=(4+3) mod 26 =7mod 26 =7=H
y5=(R+3) mod 26=(17+3) mod 26= 20 mod 26 = 20=U
y6=(E+3) mod 26=(4+3) mod 26 =7mod 26 =7=H

is tarah
encrypt ho ker ceaser cipher key sath
me here = PH KHUH

---------------------------
yeh thee encryption ab decryption key liya
mathematical equation hoti hay
x=(y+23)mod 26

is leya key ager hmm normally kertay to hoti
x=y-3 mod 26
hmm jantey haan key mod ki property haan key ager hmm 26 add ker dain to result main koi farak naeen perta. and yeh hmm normally is leya kertay han key hmm -ve value ko naeen letay

so -3 +26=23
so equation bani
x=(y+23) mod 26

ab app is equation key through khod ph khuh ko decrypt kareen
ok
------------------------------------------------

YE KIYA THA

[tauruskhan]

Re: Course :- Cryptology

YE KIYA THA

pero to pata lagey key kia tha. pera hay kia
pehlay pero pir bataoo

[Shaim]

Re: Course :- Cryptology

pero to pata lagey key kia tha. pera hay kia
pehlay pero pir bataoo

perha thaa na........bus me ka mood aj upsett hai ise liye kuch samajh bhi nahi a raha or accha bhi kuch nahi lag raha per main doobara perh leeti hon accha?:embarasse

[Shaim]

Re: Course :- Cryptology

Asalam -0-Alikum
Cryptanalysis:-
yeh bagair key kay uninteligble message ko intelligible message main transform kerna hota hay

Walikum Assalam
beghair key k????????hawa main?
crysography??????crystology hai kiya cheez??
koi software hai??
programe hai????
hai kiya cheez???
iska use kiya hai??
key kon c use hooti hai keyboard main???
koi me ka mazzaq nahi uraaye me ko computer ki ABC bhi naahi aati

[Shaim]

Re: Crytographic Algorithms

Crytographic Algorithms
in ko cipher bi bola jata hay
yeh mathematical functions hotey haan jin ko encryption and decryption key liya istamal kia jata hay

Symmmetric Algorithms
in ko conventional algorithms bi bola jata hay
symmetric algos main normally encryption and decryption key liya ik ( one ) key hi use hoti hay
is key liya zarori hay key sender and reciver communication key liya pehlay ik key per agree hoon pir communication start ho gi


Symmetric Algorithms ki tumam security us key main hoti hay
ager key ka pata lag jaey to koi bi in algos key through messages ko
encrypt and decrypt ker sakta hay

jab tak communication ko secret raknay ki zarorat ho , key bi secret raki jati hay


Types of Symmetric Algorithms:-
1. Block Algos
yeh wo ciphers hotey haan jo key groups of bit per operate kertay haan
2. Stream Algos
yeh wo ciphers hotey haan jo key individual characters per operate hotey haan , usually plaintext key binary digits per lakin aik wakat main aik

Asymmetric Algorithms:-
in ko public key algorithms bi kaha jata hay
in main encryption and decrytion key leya alag alag keys istamal hoti haan
in ko public key algorithm is leya kaha jata hay key aksar encryption key ko public ker dia jata hay , yani
key koi bi stranger encrypt ker sakta hay
lakin decrypt sirf authorized person hi keray ga

cipher,encryption,decryption........ye kiyaa cheezin hain?:pagal:

[Shaim]

Re: Course :- Cryptology

common ciphers:-

1. ceaser cipher:-
yeh nihayat simple cipher tha.
is ki mathematical equation hay

y=(x+3) mod 26

lets take an example
in cryptography we assign the values with the alphabets

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 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25

her character key nechay us ki value likhi hay

ab misal key tur per
plain text hay hamara

PT : ME HERE

y1=(M +3) mod 26 =(12+3) mod 26 = 15 mod 26 =15=P
y2=(E+3) mod 26 =(4+3) mod 26 =7mod 26 =7=H
y3= (H +3) mod 26=(7+3)mod 26=10mod 26 =10=K
y4=(E+3) mod 26=(4+3) mod 26 =7mod 26 =7=H
y5=(R+3) mod 26=(17+3) mod 26= 20 mod 26 = 20=U
y6=(E+3) mod 26=(4+3) mod 26 =7mod 26 =7=H

is tarah
encrypt ho ker ceaser cipher key sath
me here = PH KHUH

---------------------------
yeh thee encryption ab decryption key liya
mathematical equation hoti hay
x=(y+23)mod 26

is leya key ager hmm normally kertay to hoti
x=y-3 mod 26
hmm jantey haan key mod ki property haan key ager hmm 26 add ker dain to result main koi farak naeen perta. and yeh hmm normally is leya kertay han key hmm -ve value ko naeen letay

so -3 +26=23
so equation bani
x=(y+23) mod 26

ab app is equation key through khod ph khuh ko decrypt kareen
ok
------------------------------------------------

main ne is eqn ko decrypt kerney ki koshish ki hai

PHKHUH

P = 15
H = 7
K = 10
H = 7
U = 20
H = 7

According 2 the equation: X = (y+23)mod26

X1 = (y+23)mod 26 = (15+23) mod26 = 38 mod 26
X2 = (y+23)mod26 = (7+23) mod 26 = 30 mod 26
X3 = (y+23) mod 26 = (10+23) mod 26 = 33 mod 26
X4 = (y+23) mod 26 = (7+23) mod 26 = 30 mod 26
X5 = (y+23)mod 26 = (20+23) mod 26 = 43 mod 26
X6 = (y+23) mod 26 = (7+23) mod 26 = 30 mod 26


Is that correct???:pagal:

[tauruskhan]

Re: Course :- Cryptology

perha thaa na........bus me ka mood aj upsett hai ise liye kuch samajh bhi nahi a raha or accha bhi kuch nahi lag raha per main doobara perh leeti hon accha?:embarasse

keeon khareeat mood ko kia hoa :mm:

[tauruskhan]

Re: Course :- Cryptology

Walikum Assalam
beghair key k????????hawa main?
crysography??????crystology hai kiya cheez??
koi software hai??
programe hai????
hai kiya cheez???
iska use kiya hai??
key kon c use hooti hai keyboard main???
koi me ka mazzaq nahi uraaye me ko computer ki ABC bhi naahi aati

Asalam -0-ALikum
bagair keey key matalb without key (chabi ) key
yani normal tareeqay sey naeen , koi new logic laga key cipher text ko plaint text main convert ker lena

yeh cryptography , mathematical functions hotey haan jin ki madad sey simple english text ko cipher text main convert kertay haan and vice versa

kabi app ney socha app jo computer main likhti haan , wo webserver tak kia direct esay hi chala jata ho ga, koi beej main ager hook laga ker app ki baat per ker change ker lay .
to esa keeon naeen hota
is leya key app key computer sey hi message ko encript ker kay yani cipher text bana ker beja jata hay pir , us ko recieving point per decrypt ker dia jata hay

kher cryptology ki histroy to computer sey bi porani hay
world war 2 sey is ko bakaida tor per dehka gia tha , germans ney is ki behtreen form enigma machine use ki thee , lakin becharey wo bi salamat na rahey , programmers nay un ko bi break ker lia

inshallah hmm us ko bi perain gay

[tauruskhan]

Re: Course :- Cryptology

main ne is eqn ko decrypt kerney ki koshish ki hai

PHKHUH

P = 15
H = 7
K = 10
H = 7
U = 20
H = 7

According 2 the equation: X = (y+23)mod26

X1 = (y+23)mod 26 = (15+23) mod26 = 38 mod 26
X2 = (y+23)mod26 = (7+23) mod 26 = 30 mod 26
X3 = (y+23) mod 26 = (10+23) mod 26 = 33 mod 26
X4 = (y+23) mod 26 = (7+23) mod 26 = 30 mod 26
X5 = (y+23)mod 26 = (20+23) mod 26 = 43 mod 26
X6 = (y+23) mod 26 = (7+23) mod 26 = 30 mod 26


Is that correct???:pagal:

yes correct to hay lakin
ik cheeze bhol gaeen
wo yeh key end main mod to lo
mod yeh hota hay key value main sey us wakat tak 26 subtract karo jab tak wo value 26 sey kam naeen ho jati
jesay key
x1 tum ney nikali hay 38 mod 26 yahan
38 -26=12
and 12 value hay M ki
so x1 = M
baki ki shabash ab nikalo values

[tauruskhan]

Re: Crytographic Algorithms

cipher,encryption,decryption........ye kiyaa cheezin hain?:pagal:

encryption sey hmm normal text ko taroor maroor ker esa bana detay haan key asani sey us ko para na ja sakey
esi sorat main jo text banta hay us ko cipher text kehtay haan
and decryption cipher text ko wapis normal text main convert kernay ko kehtay haan

[Shaim]

Re: Crytographic Algorithms

encryption sey hmm normal text ko taroor maroor ker esa bana detay haan key asani sey us ko para na ja sakey
esi sorat main jo text banta hay us ko cipher text kehtay haan
and decryption cipher text ko wapis normal text main convert kernay ko kehtay haan

Thx a lot
i've got it
main jeet gai:lpop:

[Shaim]

Re: Course :- Cryptology

yes correct to hay lakin
ik cheeze bhol gaeen
wo yeh key end main mod to lo
mod yeh hota hay key value main sey us wakat tak 26 subtract karo jab tak wo value 26 sey kam naeen ho jati
jesay key
x1 tum ney nikali hay 38 mod 26 yahan
38 -26=12
and 12 value hay M ki
so x1 = M
baki ki shabash ab nikalo values

X1 = 12 = M
X2 = 4 = E
X3 = 7 =H
X4 = 4 =E
X5 = 17 =R
X6 = 4 = E

it is ME HERE
Main phirr jeet gaai.........me 1st aa gai
me ka inaaam kahan hai?:lpop:

[Shaim]

Re: Course :- Cryptology

keeon khareeat mood ko kia hoa :mm:

:pagal: kharaab hai ....per kal se kam:lpop: :blush:

[Shaim]

Re: Course :- Cryptology

Asalam -0-ALikum
bagair keey key matalb without key (chabi ) key
yani normal tareeqay sey naeen , koi new logic laga key cipher text ko plaint text main convert ker lena

yeh cryptography , mathematical functions hotey haan jin ki madad sey simple english text ko cipher text main convert kertay haan and vice versa

kabi app ney socha app jo computer main likhti haan , wo webserver tak kia direct esay hi chala jata ho ga, koi beej main ager hook laga ker app ki baat per ker change ker lay .
to esa keeon naeen hota
is leya key app key computer sey hi message ko encript ker kay yani cipher text bana ker beja jata hay pir , us ko recieving point per decrypt ker dia jata hay

kher cryptology ki histroy to computer sey bi porani hay
world war 2 sey is ko bakaida tor per dehka gia tha , germans ney is ki behtreen form enigma machine use ki thee , lakin becharey wo bi salamat na rahey , programmers nay un ko bi break ker lia

inshallah hmm us ko bi perain gay

Walikum Assalam

n buhaaat shukerya 4 telling me everything:salam:
oooooops main rooz encript kerti hoon or mujhko pata hi nahi tha:kr:
sab intresting hai carry on!:thmbup:
ab mujhko samajh a raha hai sab:lpop: