Introduction to Public Key Infrastructure (PKI)
and Mobile PKI concept
Pengenalan kepada Prasarana
Kekunci Awam (PKI) dan Konsep
Mobile PKI
By: Ami Azrul bin Abdullah
Notes

Dengan izin, the content of this presentation will be in
English for the ease of understanding.
PREAMBLE
A
G
E
N
D
A
BACKGROUND OF ENCRYPTION
PKI IN A NUTSHELL
PKI IN A MACRO LEVEL
MOBILE PKI CONCEPT
QUESTION AND ANSWER
3
PREAMBLE 1:
PREAMBLE 2

Preservation of Confidentiality, Integrity, Availability (CIA)
Information is observed by
or disclosed to only those
who have a right to know.
Confidentiality
Availability
Information is available and
usable when required, and the
systems that provide it can
resist attacks and recover
from failure.
Integrity
Information is accurate and
protected from unauthorized
modification.
HISTORY OF ENCRYPTION
In the beginning

The needs to encrypt/decrypt message




E.g. Ami Azrul - gqi18qhoi
Creation of Keys
Keys are drived from an algorithm/set of formulas
At first symmetric key is used
Next


The flaws of symmetric key
The Creation of Assymetric Key




Two keys are not the same yet interrelated
One cannot exist without the other
Always term as key pairs – private and public
The process done by private (secret) can only be reversed by
public (and vice versa)
Intermezzo

Symmetric – Key Pairs are the same; encrypt and decrypt


Common Algorithm :AES · Blowfish · DES · Triple DES ·
Serpent · Twofish
Assymmetric – Public and Private Key Pairs

Common examples: Diffie-Helman, ECC, RSA
Further reading: http://en.wikipedia.org/wiki/RSA or http://en.wikipedia.org/wiki/Assymetric_key_cryptography
And so..

"private key" means the key of a key pair used to create a
digital signature;
"public key" means the key of a key pair used to verify a
digital signature;
Definitions from DSA 1997
But




Keys are only algorithms ->numbers
The numbers -> keys are unique
Associate identity with keys
The birth of the Certification Authority, Registration
Authority, and of course our regulator.
PKI IN A NUTSHELL
Digital Certificates
Electronic counterparts to driver licenses, passports, membership
cards or any legal identification documents: Proof of identity
when communicating online
Contain information about the owner i.e Name, Public Key, Issuer
Name, Validity Date etc
Contain a pair of key: Private Key and Public Key
• Kept securely and safely by
the owner
• Use to generate digital signature
• Kept by the relying party, CA
or anybody who want to transact
with the owner
• Use to verify the digital signature
Digital Certificate: Sample

a) Identity of the public key
owner

b) Public Key

c) Version Number

d) Certificate serial number

e) Identity of the issuer

f) Validity period

g) Extension fields

The digital certificate’s
format is defined by CCITT
X.509 International standard
The story continues..

digital signature" means a transformation of a message using an
asymmetric cryptosystem such that a person having the initial
message and the signer's public key can accurately determine"
(a) whether the transformation was created using the private
key that corresponds to the signer's public key; and
(b) whether the message has been altered since the
transformation was made;
SOME TECHNICAL CONCEPT
The Concept of Digital Certificates - Private & Public Key
Document
Document
Document
CA via RA
private
(recipient)
public
(recipient)
secret
public
Decryption
Encryption
Digital
Signature
Document
Document
Document
Digital
Signatur
e
Internet
Intranet
Document
Document
Document
Asymmetric encryption
The quick brown
fox jumps over
the lazy dog
H88g&ikp080+h6
54gcv.&Tgf7676f
HF76yt476hTPcs
Encryption
Encrypted data
Clear data
Receivers
Public key
H88g&ikp080+h6
54gcv.&Tgf7676f
HF76yt476hTPcs
Decryption
Encrypted
data
Receivers
Private key
The quick brown
fox jumps over
the lazy dog
Clear data
cret
se
Different keys
• Suggested for the first time in 1976 by two Americans, Diffie & Hellman
• Only receiver can decrypt with his private key
• Everyone can encrypt with receiver’s public key
Digital Signature and authentication
The quick brown
fox jumps over
the lazy dog
H88g&ikp080+h6
54gcv.&Tgf7676f
HF76yt476hTPcs
Me mod n
Encrypted data
Clear data
Senders
Private key
(but not secret)
H88g&ikp080+h6
54gcv.&Tgf7676f
HF76yt476hTPcs
Re
Encrypted
data
mod n
Clear data
Senders
Public key
• Private key can be used for “encryption”
• Only sender can have generated this message!
• Used for authentication and digital signatures
The quick brown
fox jumps over
the lazy dog
WHAT DOES PKI FULFILL?

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Confidentiality
Authenticity
Integrity
Non Repudiation
PKI IN MACRO LEVEL
HOW TRUST WORKS IN PKI
Issue CA
Certificate
2
Registration
Authority
1
Register
Subscriber
Information
Certificate
Request
(Identification)
3
Accredit CA/
Trust Partner
Issue Subscriber
Certificate
Root CA
5
Validate Subscriber
Certificate
6
Validate CA
Certificate
7
4
Verify Electronic
Signature
Electronic Document Certificate
Agency
(USER)
Agency
MEDIA FOR CERTIFICATES
Key & Certificates
Storage:
Smart Card incl. MyKad
Crypto USB Token
Hard / Floppy Disk
MOBILE PHONES
AND ….
Reader Driver
for
communication
between
OS/Devices
PKI Agent/Software
needed to give card / token
function.
Similar to mobile.
MOBILE PKI CONCEPT
Background

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There are more users of smart phones than PC
On the go transaction
Concept wise: User download Agent on mobile phone:

Android, iOS, Windows and Blackberry
Socket Based Connection
1.
2.
3.
4.
5.
6.
User opens the third party’s website
User provides needed info
Third party calls the required function from our server.
Our server calls the client side app.
Client side app sent back the result
Our Server sends the result back to the server.
•The client side (phone/pc) is having two way connection
with our server.
•Third parties can issue a request for operation;
•Our server will ask the client to do that operation
•Server will send the result back to the third party.
Socket Based Connection
Functions:
-Encrypt
-Verify
-Authentication
Web Service Calling
Third Party
Application
Bidirectional Socket
GPKI Agent
Gateway Server
Functions:
-Sign
-Decrypt
Question and Answers

TERIMA KASIH