@Zacwimer
Quantum Crypto that relies on physics is only half the story; this is also post-quantum crypto that is just normal crypto done in such a way that a quantum computer would not be any more efficient at solving it than a standard computer. Quantum computers aren't magically faster than normal computers, they just function differently, in such a way that some, not all, math problems become much faster to solve. The keywords there are `not all`; there is where post-quantum crypto often lies.
@Phrenotopia
Very interesting as always! Also good to see your editing skills are getting better and better!
@johnwang9914
What you've described is conventional EOR pad cryptography with two separately securely transmitted EOR pads, not quantum cryptography. What makes quantum cryptography, quantum is using quantum entangled photons to securely communicate the spins as the spins are not determined till after the photons have been transmitted. That is, sending one photon of an entangled pair then reading the spin of your entangled photon thereby randomly setting the spin hence the transmitted photon would then become the opposite spin on the other side. Quantum cryptography is also not proof against quantum computing decryption as quantum computing allows all possible states to be evaluated simultaneously hence quantum cryptography only protects against interception of the EOR pad in conventional cryptography.
@pietheijn-vo1gt
So at 4:40, alice tells bob which filters she used for which photons only after the complete set of photons is received by Bob? Once Bob knows which filters were used for which photons, he knows which bits are correct and which bits are wrong. But Alice doesn't know this, so he has to communicate this back right? Or how does this work? The eavesdropper would read the key by filtering the photons, thus altering their spin. In that case Bob's key would be different from Alice's, but how do they detect this?
@francescosorce5189
Wait a sec if Alice and Bob used the same filter but eve used the wrong one... wouldn't that create the possibility that the digits are different? example Alice sends | eve changes it to / from here Bob could read --- when Alice and Bob call each other they'll agree they both used the + filter, but will have different digits
@DefektoPrime
Why is Eve always so nosey? Stay out of my business, Eve!!! People have the right to keep their opinion of Jar Jar private, if they so desire!
@AgentMidnight
0:51 The spoiler warning would've been much more informative if we knew what it was spoiling before you decrypted the message -__-
@mbharatm
Very well explained... I understood most of the explanation in my first view.... and that's a big achievement of yours!
@markxxx21
I have to say, I absolutely LOVE the expression on the faces when his secret is discovered. 2:35
@elijakubowicz9143
4:32 i dont get how bob and alice know that they have the same key. even if they both know that they used a diagonal filter in the second bit it could still be a 0 or a 1. so how do they know that they have the same key?????????????????????????
@erichopper4979
The Heisenberg uncertainty principle is often stated as 'nature keeps information hidden'. I think, perhaps, it would be more appropriate to say that the information simply isn't there. Basically any system can contain a limited amount of information, and if you extract the information in one form, you've gotten all information there is.
@avi12
Your videos are so professional, yet are so friendly Keep up the good work!
@animeshtalukdar1852
Why it has to be BOB and Alice everytime..
@The_Jaganath
Really interesting, I wonder if the cryptography will keep up with the rapid development of quantum computers or if they'll be widely available before the encryption - interesting times ahead.
@marcoestrada5511
I just got into cryptography and it so hard to learn it. Taking classes and reading books. I love you videos. Thank you!
@Shadow70et
Was researching on this topic. This was the simplest explanation.
@thomastingch
I viewed almost all of them, this is one of the best!
@UrbanPanic
If it turns out that encoding, transmitting and decoding the stream of quantum data takes too long, no problem. Use your quantum stream to transmit the key to a one time pad and maybe a hash for verification.
@vincentnthomas1
This is missleading: the encryption algo talked in here is AES-256. With quantum computer the cryptography hardness would go from 2^256 to 2^128, which is still considered secure. And this is only in theory. In practice this would take around 20 years
@evildracko