How the MD5 hash function works (from scratch)

Learn how the MD5 function works in detail as we break down what it does step-by-step in this animated explainer.

TIMESTAMPS
0:00 Introduction
0:53 MD5 Examples
1:25 Hexadecimal Data
2:31 Binary Operations
5:53 MD5 state
6:21 MD5 state updates
8:00 MD5 output
8:13 Combine operation
9:20 Combine examples
9:56 Combine definition
10:11 Red Box operation
11:17 Combine examples
11:45 Red box definition
12:02 Padding Algorithm
13:53 Outro

[北原春樹]

I stared at the course slide for 2 hours couldn't figure it out. And you helped me understand it within 10 minutes XD. This video deserve more views.

[petouhar]

very clear and clean explanation, thank you !

[xDarioSanchez]

Thanks man, you are really good at teaching

[elirane]

What I like about cryptography is most of the time it can be really easy to understand how it works, but WHY it works, now that is some black magic shit.
You can have a first year student implement this function, but everything about the algorithm, from the magic seeding state number to every binary operation is wild.

[nceevij]

Thanks Jeff, big fan of you and RareSkills.

[brucewayne]

Thanks, which operation makes it impossible to revert ? How do we prove that ?

[skeetabomb]

@6:32 error in dialog or graphic: dialog states "C prime = A" but graphic shows "C prime = B".

[azazahmedlipu]

Thank you a lot! As you demonstrated the MD5 hash algorithm, it seems possible to reverse it and retrieve the original input. I thought hash functions were meant to be one-way and irreversible. Could you please clarify this?

[skeetabomb]

@6:54 after first iteration, B prime has only 7 hex digits instead of 8 (0xE872CE5).

[syedbilalalam]

Bro I have a question please help me soon, "My question is what if the size of the message becomes larger than 64 bits or exactly 64bits "

[testuser]

After watching this I somehow feel MD5 is the stupidest hashing algo of all time