Dear professor, thank you from Greece! Your guides are awesome and very in-depth and explanatory! Have a good day and thank you for the amazing content!
- You should really mention more that the matrix multiplication (in mix columns) is not in normal arithmetic, but in Galois's finite field (2^8) arithmetic. Not just say "go look it up", because result with normal matrix multiplication are different. - And during key schedule you use Rcon(4) in first iteration, which is wrong. You should use number of iteration for the lookup, so Rcon(1). Visualize the XOR with only first byte, in order to be less confusive. Another iteration for next subkey is Rcon(2) in lookup table and so on. -- yeah, having rcon lookup table would also be better, rather than created vectors from the table. - Other things you are talking about are really clear and i am glad you dedicated time for making this helpful video, thanks!
also we can and will increase the AES size as needed into 1024 16*16 2bytes *4 or we can use 3 for 4096 or even 4 bytes in encription and use 256*256 which would be AES 65356 :) for the data layer. :)
Sir, I did love your video and I am just too young to understand your valuable speech as a 12 Years old. But still, I keep a large interest in Computer Science and Encryption Algorithms. Your lectures are really very much helpful. Thank you, sir!
Great video. I used the AES algorithm to encrypt and decrypt the contents of a hidden file that stored the password and username of sFTP server used to retrieve data.
Uh, well, with all due respect… NSA (part of DoD, obv) did not call for replacements to the DES or run the worldwide competition to select the algorithm to be selected to be designated as the Advanced Encryption Algorithm and incorporated into the Advanced Encryption Standard (FIPS 197). That completion was run by NIST, part of the Commerce Department. Now, NSA did decide that, at higher key lengths, when the algorithm is properly implemented, it would be sufficient to classified data up to TS. IMHO….
Hi , thanks for the awseome video . i have on question at 9:41 . why you started rotating the bytes from the second row not from the first one .. is this how the AES works or i'm missing something ? Edit: in case someone is interested for the answer i searched and found that the first rows keep unchanged 🙂 have a good day everybody.
At the end when the Round Keys are being determined from the cipher key, is this process the same regardless of the key size? I ask this because each 'key' is only 16-bytes (128-bits) so does that mean the process is slightly different for 24-byte (192-bits) and 32-byte (256-bit) keys?
Thanks for this lesson. I have a question, what cipher mode is applicable in the AES encryption? By cipher mode, I meant something like ECB, CBC, CTM, GCM, etc.
Nah, it is an XOR. Just so happens that XOR and an add for 04 and a0 has the same result. If you XOR it, it looks like this: Round 1 after MixColumns (showing only Column 1) 04 = 00000100 66 = 01100110 81 = 10000001 e5 = 11100101 RoundKey (showing only Column 1) a0 = 10100000 fa = 11111010 fe = 11111110 17 = 00010111 Now let's XOR them: 04 = 00000100 a0 = 10100000 XOR= 10100100 = A4 66 = 01100110 fa = 11111010 XOR= 10011100 = 9c 81 = 10000001 fe = 11111110 XOR= 01111111 = 7f e5 = 11100101 17 = 00010111 XOR= 11110010 = f2 Which reflects what you see in the first column at the start of Round 2 at 11:17
It's a fixed matrix for every encryption. You can find the specific matrix on wikipedia: en.wikipedia.org/wiki/Advanced_Encryption_Standard#The_MixColumns_step
Your description of MixColumns was awful. The rest was ok. Apparently a 128-bit key only provides 32-bit security since every single round key is derived from only 4-columns of which 1 is being reversibly obfuscated. It doesn't appear very secure. Figure out the obfuscated 32-bit column through brute-force, reverse the obfuscation and then finally recursively compute the other 3 key columns from the ciphertext, so that they propery match the result of the brute-forced column.
It's a pity that you skip the MixColumns part in your otherwise excellent presentation. Also, looking up matrix multiplication is not the answer to understanding this step. Thanks for the video, and please consider explaining in detail the MixColums steps.
@@alexgear959 I know but what is the order? Or how is the MixColumns step, or the key schedule done in reverse? things like that. I see everywhere tutorials and explanations just about the encryption part.
Tried to litterly find explanation how it works and only you explained the best way possible
Dear professor, thank you from Greece! Your guides are awesome and very in-depth and explanatory! Have a good day and thank you for the amazing content!
Same here lmao
This is the best explanation to AES encryption standard out here
- You should really mention more that the matrix multiplication (in mix columns) is not in normal arithmetic, but in Galois's finite field (2^8) arithmetic. Not just say "go look it up", because result with normal matrix multiplication are different.
- And during key schedule you use Rcon(4) in first iteration, which is wrong. You should use number of iteration for the lookup, so Rcon(1). Visualize the XOR with only first byte, in order to be less confusive. Another iteration for next subkey is Rcon(2) in lookup table and so on. -- yeah, having rcon lookup table would also be better, rather than created vectors from the table.
- Other things you are talking about are really clear and i am glad you dedicated time for making this helpful video, thanks!
Still best explanation found
Gotta say I'm impressed by your counter.. can you tell me some good resources to learn about AES in more detail? I'd be glad!
also we can and will increase the AES size as needed into 1024 16*16 2bytes *4 or we can use 3 for 4096 or even 4 bytes in encription and use 256*256 which would be AES 65356 :) for the data layer. :)
Thanks! Really helped alot. Learned more in this 12 mins than my whole semester
hahahah, i think in the same way, you save my life sir.
I guess you came here the night before the exam? xD
students are same everywehere)))
I was trying to understand this AES-256 concept for my startup and thank you sir prof, You help is invaluable.
the only video that has really helped me understand AES!! thank you so much
Sir, I did love your video and I am just too young to understand your valuable speech as a 12 Years old. But still, I keep a large interest in Computer Science and Encryption Algorithms. Your lectures are really very much helpful. Thank you, sir!
Thank you. I hope to see you in class soon.
What's 14 like?
Easiest explanation I've come across by far. Thanks Sir 💕
hey professor i am 13 and i am trying to learn how to encrypt using the AES algorithm ,this helped a lot to understand the process thank you
hey, did figure out how to encrypt pls message me back
I am 12 trying to understand AES, this helped! Thank you!
much more understandable and clear explanation rather than my classmate presentation
Great video. I used the AES algorithm to encrypt and decrypt the contents of a hidden file that stored the password and username of sFTP server used to retrieve data.
Thank you Shared! This short video really helped to understand the concept in simple way.
Great to hear!
Uh, well, with all due respect… NSA (part of DoD, obv) did not call for replacements to the DES or run the worldwide competition to select the algorithm to be selected to be designated as the Advanced Encryption Algorithm and incorporated into the Advanced Encryption Standard (FIPS 197). That completion was run by NIST, part of the Commerce Department. Now, NSA did decide that, at higher key lengths, when the algorithm is properly implemented, it would be sufficient to classified data up to TS. IMHO….
Wow, great explanation 🎉
Best video after I struggled on whole TH-cam video
Hi , thanks for the awseome video . i have on question at 9:41 . why you started rotating the bytes from the second row not from the first one .. is this how the AES works or i'm missing something ?
Edit: in case someone is interested for the answer i searched and found that the first rows keep unchanged 🙂 have a good day everybody.
thanks!
@@fingolfin9727 welcome 🤗
Easy to understand and nice animations. Thank you, sir
Best ever explanation of AES!
You deserve infinite likes
Thank you so much ❤️ Sir!
NIiiiiiiiiiiiiiiiceeeeeeeeeeeeeeee. Do not stop doing that, professor
a good video, i liked so much. Thank for doing this :)
At the end when the Round Keys are being determined from the cipher key, is this process the same regardless of the key size? I ask this because each 'key' is only 16-bytes (128-bits) so does that mean the process is slightly different for 24-byte (192-bits) and 32-byte (256-bit) keys?
Thanks for this lesson. I have a question, what cipher mode is applicable in the AES encryption?
By cipher mode, I meant something like ECB, CBC, CTM, GCM, etc.
Excellent! Finally understood this!
Glad you liked it!
I think there’s a mix up at 10:50, not XOR but just adding across
yea true. unless there's something we didn't understand?
Nah, it is an XOR. Just so happens that XOR and an add for 04 and a0 has the same result. If you XOR it, it looks like this:
Round 1 after MixColumns (showing only Column 1)
04 = 00000100
66 = 01100110
81 = 10000001
e5 = 11100101
RoundKey (showing only Column 1)
a0 = 10100000
fa = 11111010
fe = 11111110
17 = 00010111
Now let's XOR them:
04 = 00000100
a0 = 10100000
XOR= 10100100 = A4
66 = 01100110
fa = 11111010
XOR= 10011100 = 9c
81 = 10000001
fe = 11111110
XOR= 01111111 = 7f
e5 = 11100101
17 = 00010111
XOR= 11110010 = f2
Which reflects what you see in the first column at the start of Round 2 at 11:17
Simple explanation, thank you.
Sir, u saved my life! thank u, sir! I hope i was a student of urs that would make me invincible
Hello
thanks for the wonderful video.
anything about padding?
How does XOR work on the round key step? can anyone explain?
Beautiful! very easy to understand even if I know nothing about cryptpgraphy. I want to aplly this so baaad
Excellent presentation!
The video I wants I found here thanks sir what a great way to explain 😊☺️
loved your explanation! thanks so much
Thanks you, sir. This helped me a lot
Thanks a lot, your video is amazing! I hope you share us more video.
Could you explain the MixColumns part.
Where the matrix come from? And how to calculate to get result?
Thank you.
It's a fixed matrix for every encryption. You can find the specific matrix on wikipedia: en.wikipedia.org/wiki/Advanced_Encryption_Standard#The_MixColumns_step
Thanks. This video helped me alot.
Great overview! Thanks!
thank you sir, animation is so helpful
very helpful ,easily explained
What about decryption
very good explanation
Glad you think so!
can i get the code of AES?
this is exactly what I was looking for. thank you so much professor
You are welcome!
Hope u share more videos like this
Great Explanation
Your description of MixColumns was awful. The rest was ok.
Apparently a 128-bit key only provides 32-bit security since every single round key is derived from only 4-columns of which 1 is being reversibly obfuscated. It doesn't appear very secure. Figure out the obfuscated 32-bit column through brute-force, reverse the obfuscation and then finally recursively compute the other 3 key columns from the ciphertext, so that they propery match the result of the brute-forced column.
Well explained. Thank you
You are welcome!
Thanku sir,it was of great help
Very helpful. Thank you
great video , sr thank you very much
It's a pity that you skip the MixColumns part in your otherwise excellent presentation. Also, looking up matrix multiplication is not the answer to understanding this step. Thanks for the video, and please consider explaining in detail the MixColums steps.
I met Rijmen irl
Hallo Radboud medestudent
no explanation of what happen on each step.
great tutorial
This is called learning and A professor was supposed to be like that.
Do you have any python courses, Professor?
thanks you so much, sir!
every body talks about steps in encryption, what about decryption?
the exact opposite process of encryption
how about doing a decryption-explanation as well?
Its that but in reverse
@@alexgear959 I know but what is the order? Or how is the MixColumns step, or the key schedule done in reverse? things like that. I see everywhere tutorials and explanations just about the encryption part.
I love it jejejeje great !
Excellent !
انا مستغني عن ال 10%
Amazing!
Awesome 😎
perfect!
it helped alot
Fantastic
Thank you! Cheers!
Easy explained
Thank you. Are you a computer science student?
@@shadsluiter Yes Sir. Not Particularly. I am In 8th grade.
solid
XOR is the key
Shad the Lad
😯
+1
Great Explanation