2

- конфиденциальность- подлинность- неотчуждаемость

3

Alice Bob

S

S, OP = encrypt(O,S)

S,PO = decrypt(P,S)

P

4

plaintext

PRNG

ciphertext

key

5

A5/1,A5/2RC4Salsa20SEAL…

6

PRNG

key1

PRNG

key2

PRNG

key3

main key

7

DES3DESAESTwofish…

8

Alice Bob

A,A’,B’,OP = encrypt(O,B’)

B,B’,A’,PO = decrypt(P,B)

P

9

RSACramer-ShoupECC…

10

Alice Bob

open

secret:

public:

11

Alice Bob

a p q b

A=q^a mod p

p,q

b q pA

B=q^b mod pa p q AB

S = B^a mod p S = A^b mod p

12

S S’

MD5RIPEMDSHA1…

13

Client Server

ClientHello

ServerHello

Certificate

ServerHelloDone

ChangeCipherSpec

Finished

ChangeCipherSpec

Finished