Cryptography: Crash Course Computer Science #33
video description
Date: 2022-04-04
Related videos
Comments and reviews: 10
ansh
hey carrie (or anyone else if you would like to help), I wanted to understand that private key sharing( at 10: 00), so i thought of making myself a simple practical example out of it, but my calculations say your equation from 10: 00 is not correct. can you please have a look?
So If i have to transmit character '-P' (ascii 80 )from Boy A to B:
>> I assumed x=2 would be private key of A and y=3 would be private key of B)
>> I assumed my public key function as cipher(x, y)= (3-x % 7)-y
Thus:
- A would first Transfer cipher_a = 3-2%7 = 2 to B-
- B would first Transfer cipher_ a= 3-3%7 = 6 to A
>> I assumed my publically available encryptor function as encrypted_text = cipher(B) -x - + ascii(character)
- Thus, A would transfer the encrypted character 'P' to be as e_t = (6)-2+80 = 106
>> I assumed my publically available decryptor function as ascii(character) = encrypted_text - cipher(A) -y
- Thus, B would recieve the value as val = 106- (2)-3 = 97, which is not equal to our original value of 80
Thus (B-y mod M)-x! = (B-x mod M)-y! = (B-xy mod M)
But rather
(B-yx mod M-x) == (B-xy mod M-y) but! = B-xy %M
Is this right?
reply
hey carrie (or anyone else if you would like to help), I wanted to understand that private key sharing( at 10: 00), so i thought of making myself a simple practical example out of it, but my calculations say your equation from 10: 00 is not correct. can you please have a look?
So If i have to transmit character '-P' (ascii 80 )from Boy A to B:
>> I assumed x=2 would be private key of A and y=3 would be private key of B)
>> I assumed my public key function as cipher(x, y)= (3-x % 7)-y
Thus:
- A would first Transfer cipher_a = 3-2%7 = 2 to B-
- B would first Transfer cipher_ a= 3-3%7 = 6 to A
>> I assumed my publically available encryptor function as encrypted_text = cipher(B) -x - + ascii(character)
- Thus, A would transfer the encrypted character 'P' to be as e_t = (6)-2+80 = 106
>> I assumed my publically available decryptor function as ascii(character) = encrypted_text - cipher(A) -y
- Thus, B would recieve the value as val = 106- (2)-3 = 97, which is not equal to our original value of 80
Thus (B-y mod M)-x! = (B-x mod M)-y! = (B-xy mod M)
But rather
(B-yx mod M-x) == (B-xy mod M-y) but! = B-xy %M
Is this right?
reply
Samuel
I loved cryptography as a kid so much that I actually used to entertain myself with frequency analysis. I had a lot of books on cryptography, and I used to try to crack the examples before the book explained them, the way people try to solve mystery books before they reach the end. Now I'm falling in love with cryptography again, but with a more modern, computerized version. Thanks Crash Course!
reply
I loved cryptography as a kid so much that I actually used to entertain myself with frequency analysis. I had a lot of books on cryptography, and I used to try to crack the examples before the book explained them, the way people try to solve mystery books before they reach the end. Now I'm falling in love with cryptography again, but with a more modern, computerized version. Thanks Crash Course!
reply
Jeremy
Hot oil in the medieval ages wasn't used like you see it in Hollywood.
Oil was an expensive resources so what they would actually do is pour boiling water or extremely hot sand. Yes there was some occasions where it happened but that's an exception not the norm as it's portrayed.
reply
Hot oil in the medieval ages wasn't used like you see it in Hollywood.
Oil was an expensive resources so what they would actually do is pour boiling water or extremely hot sand. Yes there was some occasions where it happened but that's an exception not the norm as it's portrayed.
reply
Harshit
It's very nicely presented with animation. Just one problem your Rate of speech is too fast/high. Very difficult to understand if the person is not a native English speaker
reply
It's very nicely presented with animation. Just one problem your Rate of speech is too fast/high. Very difficult to understand if the person is not a native English speaker
reply
watch
-For a 128-bit keys, you'd need trillions of years to try every combination, even if you used every single computer on the planet today. So you better get started- XD
reply
-For a 128-bit keys, you'd need trillions of years to try every combination, even if you used every single computer on the planet today. So you better get started- XD
reply
Maessy
How many -key- have been said in this whole video?
I love money but I hate number.
Oh, money and number are two different things (no body ask) -
reply
How many -key- have been said in this whole video?
I love money but I hate number.
Oh, money and number are two different things (no body ask) -
reply
Kenichi
Logic Algebra 1 - 1 = 1 or 0 - 0 = 1 Pomputation. 1 + 0 = 1 Peano axiom 1 0 1 0 0 1 0 1 0 0 1 0 1. 1x = 01x Zero one x = One x = Zx Zeta (0x) = 1.
reply
Logic Algebra 1 - 1 = 1 or 0 - 0 = 1 Pomputation. 1 + 0 = 1 Peano axiom 1 0 1 0 0 1 0 1 0 0 1 0 1. 1x = 01x Zero one x = One x = Zx Zeta (0x) = 1.
reply
Blue
Wow, this was actually the exact right speed to follow, awesome graphics and amazing good comparisons. I'm actually a little happier now!
reply
Wow, this was actually the exact right speed to follow, awesome graphics and amazing good comparisons. I'm actually a little happier now!
reply
Sam
Thank you for this leacture, but please try in the next time to talk slower, so the non-English speakers can understand you better.
reply
Thank you for this leacture, but please try in the next time to talk slower, so the non-English speakers can understand you better.
reply
Elize
Maybe it would be good for YT to have a codebook. At least I would spend less time on the internet. And more time studying!
reply
Maybe it would be good for YT to have a codebook. At least I would spend less time on the internet. And more time studying!
reply
Add a review, comment
Other channel videos
