The BB84 Protocol

A short video attempting to explain the Bennett & Brassard quantum cryptography protocol.

I've omitted any mention of the particular details of quantum physics that would be involved in actual real-world implementations, such as particle polarization axes, spin, and so forth, instead replacing them with abstract "processes" and freakish mysterious "machines". The physical details (interesting though they are) are not needed to understand the basics of the protocol, and I'm no physicist, so I'd probably mess them up if I tried (assuming I haven't already!).

Making these images has increased my affection for Microsoft PowerPoint, and putting them all into a video has hugely exacerbated my hatred for Windows Movie Maker.

NOTE:
An important missing piece of information: When Alice sends qubits to Bob, she chooses between process A and process B randomly for each qubit.

NOTE 2:
The following video explains BB84 as well, and gives more detail regarding the physics details:
http://www.youtube.com/watch?v=7SMcf1MdOaQ

NOTE 3:
Here is another very interesting video about quantum cryptography. Any given real-world implementation, despite using the BB84 protocol, is bound to expose weaknesses that can be exploited. For example:
http://www.youtube.com/watch?v=T0WnUlF2eAo

Category:

Education

Tags:

• Bennett
• Brassard
• quantum cryptography
• protocol

[MrDennismar]

Great video. Thanks for the time and effort you invested in its production.

[kjlg74]

@MrDennismar It was fun to make, and was good animation practice for me. Thanks for the kind words :)

[cl0ud009]

Good job.

[kjlg74]

@cl0ud009 Thank you :)

[TehOwnerer999]

I don't think Alice and Bobs relationship is going anywhere lol... Also cool vid

[kjlg74]

You're probably right. Those long-distance quantum relationships never last :P

Actually, she won't be appearing in the next video with Bob (coming soon!) but she'll be back eventually.

[uthrarajan]

thanks!! for a practical explanation!! :)



[Surhotchaperchlorome]

@Pondenome

OK.

Thanks for the feedback. :)

[Pondenome]

@Surhotchaperchlorome That is a legitimate criticism. To remedy this, one requires that the classical channel is authenticated.

[Surhotchaperchlorome]

I was just messing. :P

I saw another video by you involving strings and stuff, and after I clicked on the link to watch this BB84 protocol, I recognized the username and the display picture.