Symmetric-Key Cryptographycs161/sp14/slides/3.12.Symmetric.pdf · Symmetric-Key Cryptography ......
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Symmetric-Key Cryptography CS 161: Computer Security Prof. David Wagner March 12, 2013
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Transcript of Symmetric-Key Cryptographycs161/sp14/slides/3.12.Symmetric.pdf · Symmetric-Key Cryptography ......
![Page 1: Symmetric-Key Cryptographycs161/sp14/slides/3.12.Symmetric.pdf · Symmetric-Key Cryptography ... Original image . ... CTR decryption uses block cipher’s encryption functionality,](https://reader031.fdocuments.us/reader031/viewer/2022022500/5aa494807f8b9ac8748c2243/html5/thumbnails/1.jpg)
Symmetric-Key Cryptography
CS 161: Computer Security Prof. David Wagner
March 12, 2013
![Page 2: Symmetric-Key Cryptographycs161/sp14/slides/3.12.Symmetric.pdf · Symmetric-Key Cryptography ... Original image . ... CTR decryption uses block cipher’s encryption functionality,](https://reader031.fdocuments.us/reader031/viewer/2022022500/5aa494807f8b9ac8748c2243/html5/thumbnails/2.jpg)
P1 P2 P3
C1 C2 C3
![Page 3: Symmetric-Key Cryptographycs161/sp14/slides/3.12.Symmetric.pdf · Symmetric-Key Cryptography ... Original image . ... CTR decryption uses block cipher’s encryption functionality,](https://reader031.fdocuments.us/reader031/viewer/2022022500/5aa494807f8b9ac8748c2243/html5/thumbnails/3.jpg)
P1 P2 P3
C1 C2 C3
![Page 4: Symmetric-Key Cryptographycs161/sp14/slides/3.12.Symmetric.pdf · Symmetric-Key Cryptography ... Original image . ... CTR decryption uses block cipher’s encryption functionality,](https://reader031.fdocuments.us/reader031/viewer/2022022500/5aa494807f8b9ac8748c2243/html5/thumbnails/4.jpg)
Original image
![Page 5: Symmetric-Key Cryptographycs161/sp14/slides/3.12.Symmetric.pdf · Symmetric-Key Cryptography ... Original image . ... CTR decryption uses block cipher’s encryption functionality,](https://reader031.fdocuments.us/reader031/viewer/2022022500/5aa494807f8b9ac8748c2243/html5/thumbnails/5.jpg)
Encrypted with ECB
![Page 6: Symmetric-Key Cryptographycs161/sp14/slides/3.12.Symmetric.pdf · Symmetric-Key Cryptography ... Original image . ... CTR decryption uses block cipher’s encryption functionality,](https://reader031.fdocuments.us/reader031/viewer/2022022500/5aa494807f8b9ac8748c2243/html5/thumbnails/6.jpg)
Later (identical) message again encrypted with ECB
![Page 7: Symmetric-Key Cryptographycs161/sp14/slides/3.12.Symmetric.pdf · Symmetric-Key Cryptography ... Original image . ... CTR decryption uses block cipher’s encryption functionality,](https://reader031.fdocuments.us/reader031/viewer/2022022500/5aa494807f8b9ac8748c2243/html5/thumbnails/7.jpg)
P1 P2 P3
C1 C2 C3
![Page 8: Symmetric-Key Cryptographycs161/sp14/slides/3.12.Symmetric.pdf · Symmetric-Key Cryptography ... Original image . ... CTR decryption uses block cipher’s encryption functionality,](https://reader031.fdocuments.us/reader031/viewer/2022022500/5aa494807f8b9ac8748c2243/html5/thumbnails/8.jpg)
P1 P2 P3
C1 C2 C3
![Page 9: Symmetric-Key Cryptographycs161/sp14/slides/3.12.Symmetric.pdf · Symmetric-Key Cryptography ... Original image . ... CTR decryption uses block cipher’s encryption functionality,](https://reader031.fdocuments.us/reader031/viewer/2022022500/5aa494807f8b9ac8748c2243/html5/thumbnails/9.jpg)
Original image
![Page 10: Symmetric-Key Cryptographycs161/sp14/slides/3.12.Symmetric.pdf · Symmetric-Key Cryptography ... Original image . ... CTR decryption uses block cipher’s encryption functionality,](https://reader031.fdocuments.us/reader031/viewer/2022022500/5aa494807f8b9ac8748c2243/html5/thumbnails/10.jpg)
Encrypted with CBC
![Page 11: Symmetric-Key Cryptographycs161/sp14/slides/3.12.Symmetric.pdf · Symmetric-Key Cryptography ... Original image . ... CTR decryption uses block cipher’s encryption functionality,](https://reader031.fdocuments.us/reader031/viewer/2022022500/5aa494807f8b9ac8748c2243/html5/thumbnails/11.jpg)
(Nonce = Same as IV)
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![Page 12: Symmetric-Key Cryptographycs161/sp14/slides/3.12.Symmetric.pdf · Symmetric-Key Cryptography ... Original image . ... CTR decryption uses block cipher’s encryption functionality,](https://reader031.fdocuments.us/reader031/viewer/2022022500/5aa494807f8b9ac8748c2243/html5/thumbnails/12.jpg)
(Note, CTR decryption uses block cipher’s encryption functionality, not decryption)
C1 C2 C3
P1 P2 P3