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Verschlüsselungsarten
Asymmetrische Verschlüsselung
Symmetrische Verschlüsselung
Geschichte
| Name | Jahr |
|---|---|
| Egypten | 1900 v.Chr. |
| Caesar Cipher | 100 v.Chr. |
| ... | ... |
| Enigma | 1933-1945 |
| Lucifer → DES → Triple DES | 1970 → 1976 → 1998 |
| AES/Rijndael | 1998 |
HALLO
+3
KDOOR
Grundlagen
XOR
| A | B | Y |
|---|---|---|
| 0 | 0 | 0 |
| 1 | 0 | 1 |
| 0 | 1 | 1 |
| 1 | 1 | 0 |
XOR-Cipher (⊕)
BAUM → 0x42 0x41 0x55 0x4D → 01000010 01000001 01010101 01001101
HUHU → 0x48 0x55 0x48 0x55 → 01001000 01010101 01001000 01010101
| 01000010 | 01000001 | 01010101 | 01001101 | (BAUM) | |
| ⊕ | 01001000 | 01010101 | 01001000 | 01010101 | (HUHU) |
| = | 00001010 | 00010101 | 00011101 | 00011000 |
AES-Verschlüsselung
Matrix-Schreibweise
ATTACK AT DAWN!
⊕
SOME 128 BIT KEY
XOR Text und Key
12 1B 19 04 63 7A 12 79 74 62 0D 15 77 05 64 58
Key expansion
E1 21 86 F2 C1 10 B4 CA E1 52 FD 9E C1 19 B8 C7
#1
...
3E A2 22 A7 98 7A 5F 4A 38 DC 25 4F EC 19 FC 49
#10
Key expansion
SOME 128 BIT KEY
Key expansion
| K |
| E |
| Y |
→
| K |
| E |
| Y |
Key expansion (sbox)
| K |
| E |
| Y |
→ ?
←
| B3 |
| 6E |
| CB |
| B7 |
Key expansion (rounding)
| B3 |
| 6E |
| CB |
| B7 |
⊕
| 01 |
| 00 |
| 00 |
| 00 |
→
| B2 |
| 6E |
| CB |
| B7 |
Key expansion (XOR 1. column)
| S |
| O |
| M |
| E |
⊕
| B2 |
| 6E |
| CB |
| B7 |
→
| E1 |
| 21 |
| 86 |
| F2 |
Key expansion (XOR 2. column)
| 1 |
| 2 |
| 8 |
⊕
| E1 |
| 21 |
| 86 |
| F2 |
→
| C1 |
| 10 |
| B4 |
| CA |
Key expansion (XOR 3. column)
| B |
| I |
| T |
⊕
| C1 |
| 10 |
| B4 |
| CA |
→
| E1 |
| 52 |
| FD |
| 9E |
Key expansion (XOR 4. column)
| K |
| E |
| Y |
⊕
| E1 |
| 52 |
| FD |
| 9E |
→
| C1 |
| 19 |
| B8 |
| C7 |
Key expansion
E1 21 86 F2 C1 10 B4 CA E1 52 FD 9E C1 19 B8 C7
#1
...
3E A2 22 A7 98 7A 5F 4A 38 DC 25 4F EC 19 FC 49
#10
Verschlüsselung
| Wiederholungen | Key size |
|---|---|
| 9 | 128 |
| 11 | 192 |
| 13 | 256 |
Verschlüsselung
XOR Text und Key
12 1B 19 04 63 7A 12 79 74 62 0D 15 77 05 64 58
Verschlüsselung
Confusion (sBox)
12 1B 19 04 63 7A 12 79 74 62 0D 15 77 05 64 58
→ ?
C9 AF D4 F2 FB DA C9 B6 92 AA D7 59 F5 6B 43 6A
Verschlüsselung
Diffusion 1
| C9 | F8 | 92 | F5 | |||
| AF | DA | AA | 6B | ← | ||
| D4 | C9 | D7 | 43 | ← | ||
| F2 | B6 | 59 | 6A | ← |
Verschlüsselung
Diffusion 1
| C9 | F8 | 92 | F5 |
| DA | AA | 6B | AF |
| D7 | 43 | D4 | C9 |
| 6A | F2 | B6 | 59 |
Verschlüsselung
Diffusion 2
C9 DA D7 6A FB AA 43 F2 92 6B D4 B6 F5 AF C9 59
→
MIX
41 6E 18 99 B9 83 DA 00 E0 95 8B 65 8B A9 38 D0
Verschlüsselung
XOR Round Key
41 6E 18 99 B9 83 DA 00 E0 95 8B 65 8B A9 38 D0
⊕
E1 21 86 F2 C1 10 B4 CA E1 52 FD 9E C1 19 B8 C7
Verschlüsselung
End-Matrix der ersten Runde
A0 4F 9E 6B 78 93 6E CA 01 C7 76 FB 4A B0 80 17
Verschlüsselung
9-fache Wiederholung der Schritte...
7D 35 4E 8B 1D C4 29 A3 00 AB AC 87 C0 50 95 1A
Endergebnis
Endergebnis
