The deep web consists of vast online content not indexed by standard search engines, including dynamic and password-protected pages, estimated to be 400-500 times larger than the surface web. Darknet, a subset of the deep web, requires special software like Tor or I2P to access hidden content using techniques such as onion and garlic routing for anonymity. Understanding how search engines work, including the limitations that prevent certain pages from being indexed, is essential for navigating these areas of the web.

2. What is Deep Web?
• The part of the World Wide Web that is not discoverable
by means of standard search engines is referred as Deep
Web.
• This includes password-protected or dynamic pages and
encrypted networks.
• The Deep Web is the majority of online content, estimated
to be 400-500 times larger than the surface web.

4. How Search Engines Work?
• Uses a spider program to fetch as many webpages as
possible.
• A program called an indexer then reads these webpages
and creates an index, storing the URL and important
content of webpage.
• Each search engine has its own ranking algorithm that
returns results based on their relevance to the user’s
specified keywords or phrases.
• To be discovered, a webpage must be static and linked to
other pages.

6. Methods which prevent web pages from being
indexed by Search Engines
• Dynamic Content
• Unlinked Content
• Private Web
• Limited Access Content
• Non-HTML Content
• Darknet Content
Can be accessed without any
additional software.

7. Darknet Content
• Certain content is intentionally hidden from the
regular Internet, accessible only with special
software, such as Tor, I2P, or other darknet
software.
• The darknets which constitute the Darknet
content include small, friend-to-friend, peer-to-
peer networks, as well as large, popular
networks like Freenet, I2P, and Tor, operated
by public organizations and individuals.

8. Types of Darknets:
• Tor (The Onion Router)
• Works on The Onion Routing
technique.

9. Types of Darknets:
• I2P (Invisible Internet Project)
• Works on The Garlic Routing
technique.

10. Types of Darknets:
• Freenet
• Works on Peer-to-Peer technique.

11. Tor:
• Tor is a network that supports onion routing; a way
to help make your traffic anonymous. Because the
Deep Web is compromised of information that
doesn’t show up on search engines, or has no
domain name registry, you must know exactly
where you are going to get there.

12. What is Onion Routing?
•Onion routing encrypts and decrypts data typically 3
or more separate times, once for each tor node it
passes through on the way to the destination via the
path given by the tor directory server.
•It does this using the public key of the router(tor
relay), which only the router’s private key can
decrypt.
•No single router knows the entire network path from
source to destination.

15. I2P (Invisible Internet Protocol):
•I2P is an anonymous network, exposing a simple
layer that applications can use to anonymously and
securely send messages to each other.
•It supports Garlic routing; in which multiple
messages are bundled together, each with its own
delivery instructions, are exposed at the end points.

16. Garlic Routing:
• Garlic routing is a variant of Onion routing that encrypts
multiple messages together to make it more difficult for
attackers to perform traffic analysis.
• To protect the identity of the sender, messages are
encrypted multiple times with the public keys of selected
nodes on the network.
• Differently from Onion routing an encrypted packet
("onion") can contain multiple packets ("cloves") with
different destinations, and the sender is not required to
specify a return path for the message.

17. Garlic Routing: