KRIPTOGRAFI and CARA KERJA SSL

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MELIA FITRIAWATI
2103 141 013
3 D3 TEKNIK INFORMATIKA A

CRYPTOGRAPHY
HOW SSL WORKS

CRYPTOGRAPHY

“Cryptography adalah ilmu atau teknik yang
digunakan untuk mengamanankan
komunikasi dan data dari gangguan musuh”

CRYPTOSYSTEM
m

E

c


ke

m : Plaintext
c : Ciphertext
ke : Encryption Key

kD
c’

D

m atau
error

E : Encryption Program
kd : Decryption Key
D : Decryption Program

In Real Life
HTTPS, the Hyper-Text Transfer Protocol with Secure

Sockets, uses both public and private-key crypto to
secure communications.
• Public key cryptography called elliptic curve DiffieHellman (ECDHE)
• Private key cryptography called the Advanced
Encryption Standard (AES)

HOW SSL WORKS

WHY SSL EXIST
ENCRYPTION
Menyembunyikan

data

yang

dikirimkan

dari


satu

komputer ke komputer lain
IDENTIFICATION
Memastikan

komputer

yang

digunakan

berkomunikasi adalah komputer yang terpercaya

untuk

ENCRYPTION – WHY?

hi!


aVlGI
g

ENCRYPTION – WHY?
Computers agree on how to
encrypt
Server sends certificate
Your computer says ‘start
encrypting’
The server says ‘start
encrypting’
All messages are now encrypted

WHO TO TRUST?
Company asks CA for a
certificate
CA creates certificate and signs
it
Certificate installed in server
Browser issued with root

certificates
Browser trusts correctly signed
certs