onion routing - jovial learning

IMPORTANT BENEFIT OF ONION

ONION AND COMPUTERS PROVIDES FREEDOM TO USERS OF COMPUTER

ANONYMITY ↔ GOSSIPS

WHY ANONYMITY IS PRACTICED IN NETWORKS ?

Privacy

Intelligence sectors

Data Security

Anonymous Communication Protocols

Mix Networks (1981)

Dining cryptographers (1988)

Onion routing (1999)

Anonymous buses (2002)

Crowds (1998)

PipeNet (1998)

Xor-trees (2000)

4

Hordes (2002)

Salsa (2006)

ISDN,pool,Stop-and-Go,timed,cascademixes

etc.

HOW ONION ROUTING WORKS ?

CORE IDEA: MIX NETWORKS

ONION ROUTING PHASES:

Setup

Transmission

Teardown

ONION ROUTING HIDES SENDING HOST AND THE RECEIVING HOST

THIS IS ANONYMITY !!!

SETUP PHASE

1. CREATE from U /CREATED (ACK from 1)

2. EXTEND/EXTENDED

3. [Repeat with layer of encryption]

[l2,CREATED]

u 1 2 3

15

TRANSMISSION PHASE

Exchanging messages in the path setup during the setup phase

TEARDOWN PHASE

After the successful delivery of message, the setup path will be destroyed.

FOR EACH BLOCK OF MESSAGE, A NEW CIRCUIT IS FORMED BETWEEN THE SOURCE AND THE DESTINATION.

How Onion Routing Works

User u running client Internet destination d

Routers running servers

u d

1 2

3

4

5

9


u d

1. u creates l-hop circuit through routers

1 2

3

4

5

9


u d


2. u opens a stream in the circuit to d

1 2

3

4

5

9


u d



3. Data are exchanged

{{{m}3}4}1 1 2

3

4

5

9


u d




{{m}3}4

1 2

3

4

5

9


u d




{m}3

1 2

3

4

5

9


u d




m

1 2

3

4

5

9


u d




m’

1 2

3

4

5

9


u d




{m’}3

1 2

3

4

5

9


u d




{{m’}3}4

1 2

3

4

5

9


u d




{{{m’}3}4}11 2

3

4

5

9


u d



3. Data are exchanged.

4. Stream is closed.

1 2

3

4

5

9


u



3. Data are exchanged.

4. Stream is closed.

5. Circuit is changed every few minutes.

1 2

3

4

5d

9

THANK YOUFor more information visit my blog pingtheprotocols.blogspot.com