Update Introduction.md

Author: deepak-malik

src/com/deepak/data/structures/Hashing/Introduction.md

@@ -1,6 +1,6 @@
 ### Hashing Introduction
 
-What is Hashing?
+#### What is Hashing?
 - Algorithm that calculates a fixed-size bit value of a given resource(block of data). 
 - Hashing transforms this data into a far shorter fixed-length value or key. 
 - The hash value can be considered the distilled summary of everything within that file.
@@ -12,13 +12,12 @@ What is Hashing?
 - If it does, this is known as a hash collision. 
 - A hash algorithm can only be considered good and acceptable if it can offer a very low chance of collision.
 
-Why do we need it?
-- A simple use case is described below, 
+#### Why do we need it?
 - If you are transferring a file from one computer to another, how do you ensure that the copied file is the same as the source? 
 - One method you could use is called hashing, which is essentially a process that translates information about the file into a code. 
 - Two hash values (of the original file and its copy) can be compared to ensure the files are equal.
 
-Benefits of Hashing?
+#### Benefits of Hashing?
 - One main use of hashing is to compare two files for equality. 
 - Without opening two document files to compare them word-for-word, the calculated hash values of these files will allow the owner to know immediately if they are different.
 - Hashing is also used to verify the integrity of a file after it has been transferred from one place to another, typically in a file backup program like SyncBack. 
@@ -27,8 +26,8 @@ Benefits of Hashing?
 - In such cases, it would be impossible to tell at a glance if two similar files are different or not, but the hash values would easily tell these files apart if they are different.
 - Ex. Verifying checksum of a deployed war or jar file on server
 
-Types of Hashing
+#### Types of Hashing
 There are many different types of hash algorithms such as RipeMD, Tiger, xxhash and more, but the most common type of hashing used for file integrity checks are MD5, SHA1 and CRC32.
-- MD5 - An MD5 hash function encodes a string of information and encodes it into a 128-bit fingerprint. MD5 is often used as a checksum to verify data integrity. However, due to its age, MD5 is also known to suffer from extensive hash collision vulnerabilities, but it’s still one of the most widely used algorithms in the world.
-- SHA1 – SHA1, developed by the National Security Agency (NSA), is a cryptographic hash function. Results from SHA1 are expressed as a 160-bit hexadecimal number. This hash function is widely considered the successor to MD5.
-- CRC32 – A cyclic redundancy check (CRC) is an error-detecting code often used for detection of accidental changes to data. Encoding the same data string using CRC32 will always result in the same hash output, thus CRC32 is sometimes used as a hash algorithm for file integrity checks.
+- **MD5** - An MD5 hash function encodes a string of information and encodes it into a 128-bit fingerprint. MD5 is often used as a checksum to verify data integrity. However, due to its age, MD5 is also known to suffer from extensive hash collision vulnerabilities, but it’s still one of the most widely used algorithms in the world.
+- **SHA1** – SHA1, developed by the National Security Agency (NSA), is a cryptographic hash function. Results from SHA1 are expressed as a 160-bit hexadecimal number. This hash function is widely considered the successor to MD5.
+- **CRC32** – A cyclic redundancy check (CRC) is an error-detecting code often used for detection of accidental changes to data. Encoding the same data string using CRC32 will always result in the same hash output, thus CRC32 is sometimes used as a hash algorithm for file integrity checks.