Storing passwords, comparing giant databases, securing credit card information…hashing algorithms do everything. Understand how hashing algorithms work.

1. How Hashing
Algorithms Work

2. Hashing Algorithm!
A complete rundown of what hashing algorithms are and how
they work
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3. Index
 What is Hashing?
 Hashing Function: The Core of Hashing
Algorithm
 Design and Working of Hashing Algorithms
 Popular Hashing Algorithms
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4. A complete rundown of what hashing algorithms
are and how they work
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 If Cryptography was a body, its Hashing Algorithm would be the heart of it.
 If Cryptography was a car, its Hashing Algorithm would be its engine.
 If Cryptography was a movie, its Hashing Algorithm would be the protagonist.
 If Cryptography was the Solar System, its Hashing Algorithm would be the Sun.
 Okay, that’s too far but you’ve got the point, right?
 Before we get to the What’s, Why’s, and How’s of a hashing algorithm, it’s important to understand where its
nuts and bolts are.
 Let’s start with Hashing.

5. What is Hashing?
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6.  Let’s try to imagine a hypothetical situation here.
Suppose, you want to send a message/file to
someone and it is of absolutely imperative that it
reaches its intended recipient in the exact same
format.
 How would you do it?
 One option is to send it multiple times and verify
that it hasn’t tampered with.
Hashing
 But, what if the message is too long?
 What if the file measures in Gigabytes?
 It would be utterly absurd, impractical and quite
frankly boring to verify every single letter, right?
 Well, that’s where Hashing comes into play.
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7. “
Using a chosen hash algorithm, data is
compressed to a fixed size. Let’s understand
this with an example. If we take the sentence
“Donkeys live a long time” and apply the
joaat hash algorithm to it, we will get 6e04f289.
This value is known as a hash.
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8.  Hashes are highly convenient when you want to identify or compare files or
databases.
 Rather than comparing the data in its original form, it’s much easier for
computers to compare the hash values.
 Whether it’s storing passwords, or in computer graphics, or in SSL
certificates…Hashing does it all.
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9. Fundamentally, Hashing is defined by two distinct
characteristics
Irreversibility
 Irreversibility points to the
fact that once you hash
something, there is no way
back. Unlike Encryption and
Encoding, you can’t easily de-
hash a message/data.
Uniqueness
 Unique, because no two
hash values are ever the
same for two different
pieces of data. If two
hashes are found to be the
same for two different
pieces of data, it’s called a
‘hash collision’ and that
algorithm becomes useless.
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10. Hashing Function: The
Core of Hashing
Algorithm
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11. Hashing Function: The Core of Hashing Algorithm
 “Behind every successful man, there is a great woman.” — Groucho Marx
 “Behind every successful hash algorithm, there is a great hash function.” – We just
made that up.
 Let’s put the jokes aside for a moment and concentrate on the crux of the matter.
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12.  A hash function is a mathematical function that converts an input value into a compressed
numerical value – a hash or hash value.
 Basically, it’s a processing unit that takes in data of arbitrary length and gives you the
output of a fixed length – the hash value.
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14. Design and Working of
Hashing Algorithms
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15. Design and Working of Hashing Algorithms
 As we discussed, a hash function lies at the heart of a hashing algorithm.
 But, to get the hash value of a pre-set length, you first need to divide the input
data into fixed sized blocks.
 This is because a hash function takes in data at a fixed-length. These blocks
are called ‘data blocks.’
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17. Design and Working of Hashing Algorithms
 The size of the data block(s) differs from one algorithm to another.
 But for a particular algorithm, it remains the same.
 For example, SHA-1 takes in the message/data in blocks of 512-bit only.
 So, if the message is exactly of 512-bit length, the hash function runs only once (80 rounds in case of
SHA-1).
 Similarly, if the message is 1024-bit, it’s divided into two blocks of 512-bit and the hash function is
run twice.
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18. Design and Working of Hashing Algorithms
 However, 99% of the time, the message won’t be in the multiples of 512-bit.
 For such cases (almost all cases), a technique called Padding is used.
 Using a padding technique, the entire message is divided into fixed-size data blocks.
 The hash function is repeated as many times as the number of data blocks.
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20. Design and Working of Hashing Algorithms
 As shown above, the blocks are processed one at a time.
 The output of the first data block is fed as input along with the second data block.
 Consequently, the output of the second is fed along with the third block and so on.
 Thus, making the final output the combined value of all the blocks.
 If you change one bit anywhere in the message, the entire hash value changes.
 This is called ‘the avalanche effect’.
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21. Popular Hashing Algorithms
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22. Whirlpool
Popular Hashing Algorithms
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Secure Hash
Algorithm
(SHA)
Message
Digest (MD)
Algorithm
RACE Integrity
Primitives
Evaluation
Message
Digest
(RIPEMD)
RSA

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