PUBLIC KEY CRYPTOSYSTEMS Symmetric Cryptosystems 23/10/2015 | pag. 2.

Public KeyCryptosystems

Symmetric Cryptosystems20/04/23 | pag. 2

Why?

Cryptography 20/04/23 | pag. 3

Why?

Cryptography 20/04/23 | pag. 4

Public Key Cryptosystems

Cryptography 20/04/23 | pag. 5

before.

Public Key Cryptosystems

Cryptography 20/04/23 | pag. 6

addressed by identification.

Public Key Cryptosystems

Cryptography 20/04/23 | pag. 7

Public Key Cryptosystems

• RSA Cryptosystem

• Rabin Encryption

• ElGamal Encryption(based on Diffie-Hellman Key Exchange)

Cryptography 20/04/23 | pag. 8

RSA

Cryptography 20/04/23 | pag. 9

RSA:Key generation

Cryptography 20/04/23 | pag. 10

RSA:Key generation

Cryptography 20/04/23 | pag. 11

RSA:Encryption

Cryptography 20/04/23 | pag. 12

RSA:Encryption – Block cipher

Cryptography 20/04/23 | pag. 13

RSA:Encryption – Block cipher

Cryptography 20/04/23 | pag. 14

RSA:Decryption

Cryptography 20/04/23 | pag. 15

We need a little of Fermat!

Intermezzo:Fermat’s Little Theorem

Cryptography 20/04/23 | pag. 16

Intermezzo:Fermat’s Little Theorem

Cryptography 20/04/23 | pag. 17

RSA:Decryption

Cryptography 20/04/23 | pag. 18

RSA:Decryption

Cryptography 20/04/23 | pag. 19

Example:RSA

Cryptography 20/04/23 | pag. 20

119147119

Security of the RSA

Cryptography 20/04/23 | pag. 21

Rabin Encryption

Cryptography 20/04/23 | pag. 22

Rabin Encryption:Key generation

Cryptography 20/04/23 | pag. 23

Rabin Encryption:Encryption

Cryptography 20/04/23 | pag. 24

Rabin Encryption:Decryption

Cryptography 20/04/23 | pag. 25

Rabin Encryption:Decryption

Cryptography 20/04/23 | pag. 26