Criptosisteme Simetrice Fluide: Rc4
This document was uploaded by user and they confirmed that they have the permission to share it. If you are author or own the copyright of this book, please report to us by using this DMCA report form. Report DMCA
Overview
Download & View Criptosisteme Simetrice Fluide: Rc4 as PDF for free.
More details
- Words: 975
- Pages: 3
Loading documents preview...
Criptosisteme simetrice fluide: RC4 n=3 23 =8 – flux de biţi Formăm vectrul S: 01234567 Alegem cheia: 26, K – vectorul cheii Codul ASCII al cheii este: 2 → 50; 6 → 54; Vectorul cheii este: 50 54 50 54 50
54
50
54
Depunem valorile codului ASCII al cheii: P 0 1 2 3
4
5
6
7
S
0
1
2
3
4
5
6
7
K
50
54
50
54
50
54
50
54
6
7
Efectuăm permutări asupra biţilor vectorului S: Iniţial i=0, j=0. j=(j+K[i]+S[j]) mod 8 1) i=0, j=(0+K[0]+S[0]) mod 8 = (0+50+0) mod 8 = 50 mod 8 = 2; SWAP(S[i],S[j])=SWAP(S[0],S[2])=21034567= 50 54 50 54 50 54 50 54 P 0 1 2 3 4 5 S
2
1
0
3
4
5
6
7
K
50
54
50
54
50
54
50
54
6
7
2) i=1, j=(2+K[1]+S[1]) mod 8 = (2+54+1) mod 8 = 57 mod 8 = 1; SWAP(S[i],S[j])=SWAP(S[1],S[1])= 21034567= 50 54 50 54 50 54 50 54 P 0 1 2 3 4 5 S
2
1
0
3
4
5
6
7
K
50
54
50
54
50
54
50
54
6
7
3) i=2, j=(1+K[2]+S[2]) mod 8 = (1+50+0) mod 8 = 51 mod 8 = 3; SWAP(S[i],S[j])=SWAP(S[2],S[3])= 21304567= 50 54 54 50 50 54 50 54 P 0 1 2 3 4 5 S
2
1
3
0
4
5
6
7
K
50
54
54
50
50
54
50
54
6
7
4) i=3, j=(3+K[3]+S[3]) mod 8 = (3+50+0) mod 8 = 53 mod 8 = 5; SWAP(S[i],S[j])=SWAP(S[3],S[5])= 21354067= 50 54 54 54 50 50 50 54 P 0 1 2 3 4 5 S
2
1
3
5
4
0
6
7
K
50
54
54
54
50
50
50
54
1
5) i=4, j=(5+K[4]+S[4]) mod 8 = (0+50+4) mod 8 = 54 mod 8 = 6; SWAP(S[i],S[j])=SWAP(S[4],S[6])= 21356047= 50 54 54 54 50 50 50 54 P 0 1 2 3 4 5 6 S 2 1 3 5 6 0 4 K 50 54 54 54 50 50 50
7 7 54
6) i=5, j=(6+K[5]+S[5]) mod 8 = (5+50+0) mod 8 = 55 mod 8 = 7; SWAP(S[i],S[j])=SWAP(S[5],S[7])= 21356740= 50 54 54 54 50 54 50 50 P 0 1 2 3 4 5 S 2 1 3 5 6 7 K 50 54 54 54 50 54
6 4 50
7 0 50
7) i=6, j=(7+K[6]+S[6]) mod 8 = (6+50+4) mod 8 = 60 mod 8 = 4; SWAP(S[i],S[j])=SWAP(S[6],S[4])= 21354760= 50 54 54 54 50 54 50 50 P 0 1 2 3 4 5
6
7
S
2
1
3
5
4
7
6
0
K
50
54
54
54
50
54
50
50
6 6 50
7 1 54
8) i=7, j=(4+K[7]+S[7]) mod 8 = (7+50+0) mod 8 = 57 mod 8 = 1; SWAP(S[i],S[j])=SWAP(S[7],S[1])= 20354761= 50 50 54 54 50 54 50 54 P 0 1 2 3 4 5 S 2 0 3 5 4 7 K 50 50 54 54 50 54 CRIPTARE Alegem un mesaj pentru criptare m = Sysadmin Iniţial i=0, j=0. i=(i+1) mod 8 = 1 mod 8 = 1. j=(j+S[i]) mod 8 = (j+S[1]) mod 8 = (0+0) mod 8 = 0 Calculam t: t=(S[i]+S[j]) mod 8 = (S[1]+S[0]) mod 8 = (0+2) mod 8 = 2 Criptul r = chr(ord(m)) XOR K[t] , K[t] = K[2] = (54)2 = (00110110)2 m[0] = S → (83)10 = (01010011)2 m[1] = y → (121)10 = (01111001)2 m[2] = s → (115)10 = (01110011)2 m[3] = a → (97)10 = (01100001)2 m[4] = d → (100)10 = (01100100)2 m[5] = m → (109)10 = (01101101)2 m[6] = i → (105)10 = (01101001)2 m[7] = n → (110)10 = (01101110)2 1) r[0] = 01010011 XOR 00110110 = (01100101)2 = (101)10 → e 2
2) 3) 4) 5) 6) 7) 8)
r[1] = 01111001 XOR 00110110 = (01001111)2 = (79)10 → O r[2] = 01110011 XOR 00110110 = (01000101)2 = (69)10 → E r[3] = 01100001 XOR 00110110 = (01010111)2 = (87)10 → W r[4] = 01100100 XOR 00110110 = (01010010)2 = (82)10 → R r[5] = 01101101 XOR 00110110 = (01011011)2 = (91)10 → [ r[6] = 01101001 XOR 00110110 = (01011111)2 = (95)10 → _ r[7] = 01101110 XOR 00110110 = (01011000)2 = (88)10 → X
Deci, mesajul m = „Sysadmin” criptat este „eOEWR[_X” DECRIPTARE Cript r = eOEWR[_X; K=26; S= 20354761 P 0
1
2
3
4
5
6
7
S
2
0
3
5
4
7
6
1
K
50
50
54
54
50
54
50
54
Iniţial i=0, j=0. i = (i+1) mod 8 = 1 mod 8 = 1. j = (j+S[i]) mod 8 = (j+S[1]) mod 8 = (0+0) mod 8 = 0 Calculam t: t=(S[i]+S[j]) mod 8 = (S[1]+S[0]) mod 8 = (0+2) mod 8 = 2 i = chr(ord(r)) XOR K[t] r[0] = e → (101)10 = (01100101)2 r[1] = O → (79)10 = (01001111)2 r[2] = E → (69)10 = (01000101)2 r[3] = W → (87)10 = (01010111)2 r[4] = R → (82)10 = (01010010)2 r[5] = [ → (91)10 = (01011011)2 r[6] = _ → (95)10 = (01011111)2 r[7] = X → (88)10 = (01011000)2 1) 2) 3) 4) 5) 6) 7) 8)
m[0] = 01100101 XOR 00110110 = (01010011)2 = (83)10 → S m[1] = 01001111 XOR 00110110 = (01111001)2 = (121)10 → y m[2] = 01000101 XOR 00110110 = (01110011)2 = (115)10 → s m[3] = 01010111 XOR 00110110 = (01100001)2 = (97)10 → a m[4] = 01010010 XOR 00110110 = (01100100)2 = (100)10 → d m[5] = 01011011 XOR 00110110 = (01101101)2 = (109)10 → m m[6] = 01011111 XOR 00110110 = (01101001)2 = (105)10 → i m[7] = 01011000 XOR 00110110 = (01101110)2 = (110)10 → n
Mesajul criptat r = „eOEWR[_X” decriptat va fi: „Sysadmin”. 3
54
50
54
Depunem valorile codului ASCII al cheii: P 0 1 2 3
4
5
6
7
S
0
1
2
3
4
5
6
7
K
50
54
50
54
50
54
50
54
6
7
Efectuăm permutări asupra biţilor vectorului S: Iniţial i=0, j=0. j=(j+K[i]+S[j]) mod 8 1) i=0, j=(0+K[0]+S[0]) mod 8 = (0+50+0) mod 8 = 50 mod 8 = 2; SWAP(S[i],S[j])=SWAP(S[0],S[2])=21034567= 50 54 50 54 50 54 50 54 P 0 1 2 3 4 5 S
2
1
0
3
4
5
6
7
K
50
54
50
54
50
54
50
54
6
7
2) i=1, j=(2+K[1]+S[1]) mod 8 = (2+54+1) mod 8 = 57 mod 8 = 1; SWAP(S[i],S[j])=SWAP(S[1],S[1])= 21034567= 50 54 50 54 50 54 50 54 P 0 1 2 3 4 5 S
2
1
0
3
4
5
6
7
K
50
54
50
54
50
54
50
54
6
7
3) i=2, j=(1+K[2]+S[2]) mod 8 = (1+50+0) mod 8 = 51 mod 8 = 3; SWAP(S[i],S[j])=SWAP(S[2],S[3])= 21304567= 50 54 54 50 50 54 50 54 P 0 1 2 3 4 5 S
2
1
3
0
4
5
6
7
K
50
54
54
50
50
54
50
54
6
7
4) i=3, j=(3+K[3]+S[3]) mod 8 = (3+50+0) mod 8 = 53 mod 8 = 5; SWAP(S[i],S[j])=SWAP(S[3],S[5])= 21354067= 50 54 54 54 50 50 50 54 P 0 1 2 3 4 5 S
2
1
3
5
4
0
6
7
K
50
54
54
54
50
50
50
54
1
5) i=4, j=(5+K[4]+S[4]) mod 8 = (0+50+4) mod 8 = 54 mod 8 = 6; SWAP(S[i],S[j])=SWAP(S[4],S[6])= 21356047= 50 54 54 54 50 50 50 54 P 0 1 2 3 4 5 6 S 2 1 3 5 6 0 4 K 50 54 54 54 50 50 50
7 7 54
6) i=5, j=(6+K[5]+S[5]) mod 8 = (5+50+0) mod 8 = 55 mod 8 = 7; SWAP(S[i],S[j])=SWAP(S[5],S[7])= 21356740= 50 54 54 54 50 54 50 50 P 0 1 2 3 4 5 S 2 1 3 5 6 7 K 50 54 54 54 50 54
6 4 50
7 0 50
7) i=6, j=(7+K[6]+S[6]) mod 8 = (6+50+4) mod 8 = 60 mod 8 = 4; SWAP(S[i],S[j])=SWAP(S[6],S[4])= 21354760= 50 54 54 54 50 54 50 50 P 0 1 2 3 4 5
6
7
S
2
1
3
5
4
7
6
0
K
50
54
54
54
50
54
50
50
6 6 50
7 1 54
8) i=7, j=(4+K[7]+S[7]) mod 8 = (7+50+0) mod 8 = 57 mod 8 = 1; SWAP(S[i],S[j])=SWAP(S[7],S[1])= 20354761= 50 50 54 54 50 54 50 54 P 0 1 2 3 4 5 S 2 0 3 5 4 7 K 50 50 54 54 50 54 CRIPTARE Alegem un mesaj pentru criptare m = Sysadmin Iniţial i=0, j=0. i=(i+1) mod 8 = 1 mod 8 = 1. j=(j+S[i]) mod 8 = (j+S[1]) mod 8 = (0+0) mod 8 = 0 Calculam t: t=(S[i]+S[j]) mod 8 = (S[1]+S[0]) mod 8 = (0+2) mod 8 = 2 Criptul r = chr(ord(m)) XOR K[t] , K[t] = K[2] = (54)2 = (00110110)2 m[0] = S → (83)10 = (01010011)2 m[1] = y → (121)10 = (01111001)2 m[2] = s → (115)10 = (01110011)2 m[3] = a → (97)10 = (01100001)2 m[4] = d → (100)10 = (01100100)2 m[5] = m → (109)10 = (01101101)2 m[6] = i → (105)10 = (01101001)2 m[7] = n → (110)10 = (01101110)2 1) r[0] = 01010011 XOR 00110110 = (01100101)2 = (101)10 → e 2
2) 3) 4) 5) 6) 7) 8)
r[1] = 01111001 XOR 00110110 = (01001111)2 = (79)10 → O r[2] = 01110011 XOR 00110110 = (01000101)2 = (69)10 → E r[3] = 01100001 XOR 00110110 = (01010111)2 = (87)10 → W r[4] = 01100100 XOR 00110110 = (01010010)2 = (82)10 → R r[5] = 01101101 XOR 00110110 = (01011011)2 = (91)10 → [ r[6] = 01101001 XOR 00110110 = (01011111)2 = (95)10 → _ r[7] = 01101110 XOR 00110110 = (01011000)2 = (88)10 → X
Deci, mesajul m = „Sysadmin” criptat este „eOEWR[_X” DECRIPTARE Cript r = eOEWR[_X; K=26; S= 20354761 P 0
1
2
3
4
5
6
7
S
2
0
3
5
4
7
6
1
K
50
50
54
54
50
54
50
54
Iniţial i=0, j=0. i = (i+1) mod 8 = 1 mod 8 = 1. j = (j+S[i]) mod 8 = (j+S[1]) mod 8 = (0+0) mod 8 = 0 Calculam t: t=(S[i]+S[j]) mod 8 = (S[1]+S[0]) mod 8 = (0+2) mod 8 = 2 i = chr(ord(r)) XOR K[t] r[0] = e → (101)10 = (01100101)2 r[1] = O → (79)10 = (01001111)2 r[2] = E → (69)10 = (01000101)2 r[3] = W → (87)10 = (01010111)2 r[4] = R → (82)10 = (01010010)2 r[5] = [ → (91)10 = (01011011)2 r[6] = _ → (95)10 = (01011111)2 r[7] = X → (88)10 = (01011000)2 1) 2) 3) 4) 5) 6) 7) 8)
m[0] = 01100101 XOR 00110110 = (01010011)2 = (83)10 → S m[1] = 01001111 XOR 00110110 = (01111001)2 = (121)10 → y m[2] = 01000101 XOR 00110110 = (01110011)2 = (115)10 → s m[3] = 01010111 XOR 00110110 = (01100001)2 = (97)10 → a m[4] = 01010010 XOR 00110110 = (01100100)2 = (100)10 → d m[5] = 01011011 XOR 00110110 = (01101101)2 = (109)10 → m m[6] = 01011111 XOR 00110110 = (01101001)2 = (105)10 → i m[7] = 01011000 XOR 00110110 = (01101110)2 = (110)10 → n
Mesajul criptat r = „eOEWR[_X” decriptat va fi: „Sysadmin”. 3
Related Documents
Criptosisteme Simetrice Fluide: Rc4
January 2021 1More Documents from "Anton Andrian"
Criptosisteme Simetrice Fluide: Rc4
January 2021 1
Hipnoterapi, Healing Terapi, Hipno Heart Terapi
January 2021 1
