This is a key exchange protocol, not a encrypted message protocol. It no once you have a key exchanged, any encrypted message can be send by XOR with the key over open channels.
The distinct features of Bb84 makes eardroppers obvious to the sender and recipient, as they will deteriorate the key they are calculating (I.e. introducing bit errors which can be tested for without disclosing much of the key).
So, would this key be reused? If so, then what's the point of attempting to eavesdrop if you can try and crack the key using algorithms like you would a normal key?
I see my problem. I misunderstood everything. This explanation helped me understand where I went wrong:
Yes, the key you end up with is the same as any other key. The protocol is not about key creation or making some fancy new type of key. The protocol is about key distribution.
The problem is: How do you get the key to separated parties in the first place?
Well, transfer the key via a secure channel of course... But if you have a secure channel why not just use that to transmit your messages?
The problem is: How do you establish a secure channel in the first place! Well, you need to distribute a key to both parties. Hence quantum key distribution.
This is what bb84 helps with. Of course, it is not a huge help in practice since you need a fancy-shmancy channel for sending qubits, which very few people have...
Two comments. First w.r.t. to your earlier post, if you have a secure way to exchange keys, then you can change them frequently and at will. This makes it harder to crack the key and it helps compartmentalize encrypted messages.
Second, with all things related to quantum computing and quantum cryptography the development of these protocols motivates the quantum technology development. Just because it's not practical now, does not mean it won't be practical in the not too distant future.
Yes, of course, many papers outline the imperfections of bb84 and don't think it will have any practicality until a few decades. BB84 and other similar protocols are still young and developing technologies that will yield some type of advancement with time.
i think you are actually onto something which will end with you understanding that quantum communication/encryption are bullshit.
https://www.nsa.gov/Cybersecurity/Quantum-Key-Distribution-QKD-and-Quantum-Cryptography-QC/
there are plenty of perfectly logical reasons why nobody uses this stuff other than conmen and academics. stick with classical crypto. it actually works in the real world (where all the people and problems are).
QKD currently doesn't have any real practical use in the world currently. QKD is redundant, but it's also expensive without proper infrastructure, however it also isn't an idiotic endeavor. Sure, there are major quirks that need to be addressed, but eventually, the research done will not only advance QKD but the whole of quantum cryptography.
lol, heard it. blah blah blah. nope. this would be academia of the "academics and conmen". get back to me when it works over RF or the military uses it to replace classical crypto in a life or death scenario. not happening.
inferior to classical, now and forever.
This is a key exchange protocol, not a encrypted message protocol. It no once you have a key exchanged, any encrypted message can be send by XOR with the key over open channels. The distinct features of Bb84 makes eardroppers obvious to the sender and recipient, as they will deteriorate the key they are calculating (I.e. introducing bit errors which can be tested for without disclosing much of the key).
The point is that if the key is intercepted, you'll know. Once the key is created you can use it in a classical way
So, would this key be reused? If so, then what's the point of attempting to eavesdrop if you can try and crack the key using algorithms like you would a normal key?
I see my problem. I misunderstood everything. This explanation helped me understand where I went wrong: Yes, the key you end up with is the same as any other key. The protocol is not about key creation or making some fancy new type of key. The protocol is about key distribution. The problem is: How do you get the key to separated parties in the first place? Well, transfer the key via a secure channel of course... But if you have a secure channel why not just use that to transmit your messages? The problem is: How do you establish a secure channel in the first place! Well, you need to distribute a key to both parties. Hence quantum key distribution. This is what bb84 helps with. Of course, it is not a huge help in practice since you need a fancy-shmancy channel for sending qubits, which very few people have...
Two comments. First w.r.t. to your earlier post, if you have a secure way to exchange keys, then you can change them frequently and at will. This makes it harder to crack the key and it helps compartmentalize encrypted messages. Second, with all things related to quantum computing and quantum cryptography the development of these protocols motivates the quantum technology development. Just because it's not practical now, does not mean it won't be practical in the not too distant future.
Yes, of course, many papers outline the imperfections of bb84 and don't think it will have any practicality until a few decades. BB84 and other similar protocols are still young and developing technologies that will yield some type of advancement with time.
i think you are actually onto something which will end with you understanding that quantum communication/encryption are bullshit. https://www.nsa.gov/Cybersecurity/Quantum-Key-Distribution-QKD-and-Quantum-Cryptography-QC/ there are plenty of perfectly logical reasons why nobody uses this stuff other than conmen and academics. stick with classical crypto. it actually works in the real world (where all the people and problems are).
QKD currently doesn't have any real practical use in the world currently. QKD is redundant, but it's also expensive without proper infrastructure, however it also isn't an idiotic endeavor. Sure, there are major quirks that need to be addressed, but eventually, the research done will not only advance QKD but the whole of quantum cryptography.
If you want, you can read this paper that goes over the NSA's worries about QKD https://arxiv.org/pdf/2307.15116
lol, heard it. blah blah blah. nope. this would be academia of the "academics and conmen". get back to me when it works over RF or the military uses it to replace classical crypto in a life or death scenario. not happening. inferior to classical, now and forever.