AES Encryption 2: AddRoundKey, SubBytes and ShiftRows

In this vid we'll fill out the bodies to three of the steps in AES. These three steps are AddRoundKey, SubBytes and ShiftRows. The remaining steps to AES are rather fiddly, MixColumns and ExpandKey, so we'll look at those separately.
I've also taken the opportunity to introduce Galois fields for the AddRoundKey section. AddRoundKey is really just a matter of performing XOR, but it helps to understand Galois fields before we come to the MixColumns step.
Link to the S_Box on Wikipedia:
en.wikipedia.o...
Link to the Finite Field/Galois Field Wikipedia page:
en.wikipedia.o...
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[@Cubinator73]

I like how you explain this _AddRoundKey_ thing and it just comes out to be an XOR operation :D

[@majoro7251]

Yep! xD

[@oler2322]

To be honest, this is probably one of the best and easiest coding video I've ever seen. Thank you!

[@MrGreeneyes77]

Utterly fantastic video(s)! It's so rare to find something this well done by a native english speaker!

[@nomen385]

Ikr...always d indians doing it

[@JOBEEHUSTLER]

Thank you for making me understand this so clearly.

[@ImmortalSoul52]

You sir, are a lifesaver and legend!!

[@bakkasur9614]

i am loving these "Short stories long!" @19:29....Thanks alot! you should do more cryptograph stuff. you make it look easy.

[@sethrigney5978]

This is very helpful. It's hard programming in college when your hobby isn't writing programs. I end up having to revive my programming experience after months or a year of not writing any programs lol. I am not even in computer science but it is required for my cyber security degree :(

[@SphereofTime]

5:59

[@Marshalldsfs]

Thank you for sharing this, feel it's very usefully

[@WhatsACreel]

You're welcome, cheers for watching :)

[@reshabprasad6793]

Can u provide us a full source code of this above AES explanation?

[@timgerard262]

G'day mate, from the USA!

[@WhatsACreel]

G'day mate, from Oz :)

[@greenarthur6602]

can someone please explain to me on why he is using pointers on his parameters for for the steps?? I dont get it??????

[@neevpenkar4955]

Dear Creel, why are the bytes arranged as 0, 4, 8, 12, and not as 0, 1, 2, 3? In essence, why have you taken them as column vectors and not as row vectors? At least for me, it is somehow more intuitive to have them arranged horizontally. Is AES just programmed that way?

[@AudicyVEVO]

"In case you were doing AES by hand, which you would never do." Me: god I hate my professor for making me do it by hand

[@yungjoshx]

same this shit sucks man

[@theresatobollik2382]

Thank you so much. So well explained.

[@Anonymous-pr3gr]

Honestly, the wiki page makes it way more complicated than it actually is. Although, i am so happy to know how to operate on bytes now (not that it's hard) cuz i was doing some ciphers before directly on the text. It has terrible.

[@abbasssharara2393]

if anyone want to create those instruction he wrote for shift rows as a loop here it is: char tmp; int j = 0; int i = 0; for ( i = 1; i

[@eman548]

what is the initial value of Roundkey in its function ?

[@bhalsodnirva104]

Can you share a link for the code?

[@zainabayub8025]

can anybody gives me link of s-box genrated how specifically that s-box of hexa num can be created . I wanted to know those values like E3 6C and bla bla words put in that table

[@ammisaid8273]

GALELOIO FIELDS IS COOOOOL !!!!!!

[@mrclipent3708]

So you at 18:00 , you're doing the AND operation and not the XOR operation?

[@WhatsACreel]

It's XOR. Adding the bits without recording the carry. It's the same as asking if the bits are not equal. If they're not equal, record a 1, otherwise record 0. Hope this helps, cheers for watching :)

[@chigoziea.991]

Can't understand how they match at the AddRoundKey step :P.

[@xRockbandObsessionx]

So do you use 16 inside all of your arrays because your key is 16 bytes? Also, for 256 instead of 128, would it become 32 bytes and the key array consist of 32 numbers? Great videos :) Thanks!

[@IamNotNewHere]

thank you so much!

[@nlkhoshiro]

thank you an amazing video!

[@sree6119]

Which software you have used ..is that python or visual studio??

[@marcosdaniel4237]

Could you make the file available?

[@yashbansal7205]

when you are using subbytes state[i]=s_box[state[i]] here state[i] is a character so how can you pass it in s box parameter

[@creelsmusic5814]

It's not a parameter, more like an array index. We're swapping state[i] for the value in the s box with the same number. So if state[i] is 10, then it will be swapped with whatever is in the s box at the 10th position.

[@yashbansal5655]

Creel's Music but you have copied message in state so it can also contain letter like 'T' so than which value og sbox will it take.

[@creelsmusic5814]

'T' is just a number. It's really the ASCII number of the character. 'T' has ASCII of 84, so it would be swapped with whatever is at the index 84 in the s box

[@asdfg2466]

Is the code or the program uploaded somewhere?

[@roykimor]

I always feel stupid when it comes to cryptography, I can implement any cryptography given instruction, but understanding why it does what it does and how it makes it secure enough to be a "standard", is beyond my understanding and I can't find good explanation for it. So regarding to what I said, mind answering these question about AES ?

[@INT41O]

+Roy Mor it's all about confusion and diffusion: en.wikipedia.org/wiki/Confusion_and_diffusion SubBytes corresponds to confusion, the rest to diffusion i think

[@JensHove]

A loop to move 16 bytes. Can't you make a Move(Source,Dest,SizeOf(Source)) in C#??

[@ElementzDiMetaphysics98]

I typed the whole entire S-Box out lol hahaha

[@Shan-gn7mg]

I like your accent xD

[@hassan4834]

could you please provide the source code of aes 128 bit.

[@WhatsACreel]

Sorry mate, I don't have a working website at the moment. Also, a recent crash lost most of the sources from these vids. Good luck, have a good one!

[@hassan4834]

OK no worries. btw you have done a great job thank you :)

[@건강나라-f3v]

awsome

[@churchboy2334]

where is the source code. please push it to your github repository

[@douwehuysmans5959]

Please indent the code :/

[@faythaan7056]

my code won't run T_T

[@WhatsACreel]

Tell me about it! Mine breaks too. Well, just gotta keep on keeping on mate. Step through, check everything... Debugging is hard! Hope you can track down the problem mate. Thanks for watching :)

[@farrasmuttaqin9091]

please implement in android studio

[@chimpionboy]

About the chess game hope I would like to beat the crap out it . lol just kidding I don't have a clue about chess game.

[@WhatsACreel]

I love chess, I am terrible at it though. I'd like to make an engine, but at the moment, there is no chance. Anywho, thanks for watching, have a good one!

[@WhatsACreel]

PS. I just watched your vids, your accent is amazing dude!

[@MrPlayermacik]

amazing video, thank you!