ASSIGNMENT:1

SUBMITTED BY:

NAME: LINTA SHAH

ROLL NO: 08

DEPARTMENT: COMPUTER SCIENCE

SEMESTER: 6th

SUBJECT: INFORMATION SECURITY

SESSION: 2020-2024

SUBMITTED TO:

LECTURER: MA’AM NADIA GUL

SUBMISSION DATE: 2ND MAY, 2023 TUESDAY

INTRODUCTION:

MD5 was invented by Ron Rivest in 1991 to restore an earlier hash

function MD4. The algorithm creates an input a message of arbitrary length
and makes as output a 128-bit fingerprint or message digest of the input.

WHAT IS MD5?

MD5 (message-digest algorithm) is a cryptographic protocol used for

authenticating messages as well as content verification and digital
signatures. MD5 is based on a hash function that verifies that a file you
sent matches the file received by the person you sent it to. Previously, MD5
was used for data encryption, but now it’s used primarily for authentication.

HOW DOES MD5 WORK?

MD5 runs entire files through a mathematical hashing algorithm to generate

a signature that can be matched with an original file. That way, a received
file can be authenticated as matching the original file that was sent,
ensuring that the right files get where they need to go.

The MD5 hashing algorithm converts data into a string of 32 characters.

For example, the word “frog” always generates this hash:
938c2cc0dcc05f2b68c4287040cfcf71. Similarly, a file of 1.2 GB also
generates a hash with the same number of characters. When you send that
file to someone, their computer authenticates its hash to ensure it matches
the one you sent.

If you change just one bit in a file, no matter how large the file is, the hash
output will be completely and irreversibly changed. Nothing less than an
exact copy will pass the MD5 test.

WHAT IS MD5 USED FOR?

MD5 is primarily used to authenticate files. It’s much easier to use the MD5
hash to check a copy of a file against an original file than to check bit by bit
to see if the two copies match.
MD5 was once used for data security and encryption, but these days its
primary use is authentication. Because a hacker can create a file that has
the exact same hash as an entirely different file, MD5 is not secure in the
event that someone tampers with a file. But if you’re simply copying a file
from one place to another, MD5 will do the job.

USES:

There are various uses of MD5 Algorithm are as follows –

 The MD5 Algorithm is designed for digital signature application,

where a high file should be compressed in a safe manner before
being encrypted with a private key under a public key cryptosystem
including RSA.
 The MD5 Algorithm designed to be rapid on 32-bit devices. Moreover,
the MD5 algorithm does not needed any high substitution tables and
the algorithm can be coded quite compactly.
 The MD5 Algorithm is an enlargement of the MD4 message digest
algorithm. MD5 is somewhat slower than MD4, but is more traditional
in design.
 It can be used for the goals of data verification in transmission
protocols
 In several web applications, MD5 hash can be used to avoid security
breaches, hacking etc. by the method of improving security.

STEPS IN MD5 ALGORITHM:

The following are the steps of the MD5 algorithm:

PADDING: The input message is padded with extra bits to make it a

multiple of 512 bits long. The padding includes a 1 bit, followed by enough
0 bits to bring the length up to 64 bits fewer than a multiple of 512. The last
64 bits of the padded message are used to store the length of the original
message.
INITIALIZATION: The MD5 algorithm uses four 32-bit words, labeled A, B,
C, and D, as state variables. These are initialized to fixed constants at the
beginning of the algorithm.

PROCESSING: The padded message is divided into 512-bit blocks, and

each block is processed by the MD5 algorithm. Each block is first broken
up into sixteen 32-bit words. Then, a series of 64 operations is performed
on these words, using the state variables A, B, C, and D, as well as a table
of constants derived from the sine function.

OUTPUT: After all the blocks have been processed, the state variables A,
B, C, and D contain a 128-bit message digest, which is the output of the
MD5 algorithm.

Overall, the MD5 algorithm uses a combination of bitwise logical

operations, modular arithmetic, and simple algebraic functions to produce a
hash value that is highly unlikely to collide with the hash values produced
for other input messages.

FIREWALL:

A firewall is a network security device that monitors incoming and outgoing

network traffic and decides whether to allow or block specific traffic based
on a defined set of security rules.

USES OF FIREWALL:

A firewall is an essential component of the system.A firewall can be

hardware, software, software-as-a service (SaaS), public cloud, or private
cloud (virtual).

1. Prevents the Passage of Unwanted Content.

2. Prevents Unauthorized Remote Access.

3. Prevents Indecent Content.

4. Guarantees Security Based on Protocol and IP Address.

5. Prevents Destructive Content from Online Videos and Games.

TYPES OF FIREWALL:

 Packet-filtering Firewalls.
 Circuit-level Gateways.
 Application-level Gateways (Proxy Firewalls)
 Stateful Multi-layer Inspection (SMLI) Firewalls.
 Next-generation Firewalls (NGFW)
 Threat-focused NGFW.
 Network Address Translation (NAT) Firewalls.
 Cloud Firewalls.

CONCLUSION:

A firewall is a cyber-security tool that protects systems when operating on

the internet. With so much malicious content being floated across the
internet web, it is essential to keep the systems secure. It doesn’t matter in
which form firewalls exist, only that they protect the systems effectively.