1323: Protocol

Explain xkcd: It's 'cause you're dumb.
Revision as of 07:01, 29 January 2014 by (talk) (Explanation)
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Changing the names would be easier, but if you're not comfortable lying, try only making friends with people named Alice, Bob, Carol, etc.
Title text: Changing the names would be easier, but if you're not comfortable lying, try only making friends with people named Alice, Bob, Carol, etc.


Ambox notice.png This explanation may be incomplete or incorrect: check grammar, explain better Alice and Bob, and adding links to other comics related with cryptography
If you can address this issue, please edit the page! Thanks.

Alice, Bob and Eve are names usually used in cryptographic conversations. Usually Alice wants to send a secret message to Bob, and Eve is a malicious attacker that wants to read the message (More info on wikipedia: [1]).

The joke here is that any computer scientist will react to the names, thinking that they are listening a example about criptography. By using this, you can force them to listen any boring story just by changing the names, and using the list of names usually used in these examples (Alice, Bob, Eve, Dan...)

The title text just shows a more radical approach to the problem, for the people who dont want to lie. In this approach instead of changing the names, you try to only make friends with people named like them.


[Cueball is telling a story to a Computer Scientist who is seated at his desk.]
Cueball: Alice sends a message to Bob saying to meet her somewhere.
Computer Scientist: Uh huh.
Cueball: But Eve sees it, too, and goes to the place.
Computer Scientist: With you so far.
Cueball: Bob is delayed, and Alice and Eve meet.
Computer Scientist: Yeah?
I've discovered a way to get computer scientists to listen to any boring story.

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This is funny. I was really drawn into the conversation due to the names. 07:05, 29 January 2014 (UTC)

Me too! And I'm even more drawn to the meta-conversation!!  :) Nealmcb (talk) 13:30, 29 January 2014 (UTC)
But what about me? Alice and Bob get way too much time already.... Carol (whisper) 13:30 29 January 2014 (UTC)

Eve appears in 177: Alice and Bob --JakubNarebski (talk) 08:14, 29 January 2014 (UTC)

Heh. I was immediately reminded of the movie, Bob & Carol & Ted & Alice. http://www.imdb.com/title/tt0064100/ I wonder if that movie influenced the encryption names, or vice versa, or mere coincidence? 12:31, 29 January 2014 (UTC)

I think the explanation looks complete to me. I vote to remove the tag. Jarod997 (talk) 14:04, 29 January 2014 (UTC)

Removed then. There was someone who asked for more Cryptography comic references. I found 14 and have thus made a new category (see link below). Feel free to add more if I have not found them all by searching on Cryptography and Encryption (I have only included those where there were some direct mention of these issues in the commic - or title text) and not just because there was mention of it in the explanation. However, the words does not have to appear in the commic before I included them. i.e. PGP. But also feel free to delete one from the list if I was too quick to include it Kynde (talk) 15:45, 29 January 2014 (UTC)

The description misses a key aspect of the comic. The conversation follows the pattern of a message being sent from Cueball to the Computer Scientist, with the CS sending an acknowledgement back and Cueball continuing --- much in the matter of an internet communication protocol, as referenced in the title. JamesCurran (talk) 17:06, 29 January 2014 (UTC)

I added a bit of text regarding the possible extra joke in the comic title. 03:01, 18 February 2015 (UTC)

Really excellent explanation. Complete, concise and well written, with some helpful notes in the comments. Keep up the good work! 18:43, 29 January 2014 (UTC)

I agree this would explain the protocol title, but how does it compute with the message at the bottom: I've discovered a way to get computer scientists to listen to any boring story? Kynde (talk) 18:55, 29 January 2014 (UTC)

The point is that Cueball tells a completely mundane and booooring! story (might be last evening's soap opera, for example), but by replacing the protagonist names with Alice, Bob and Eve, names commonly used in explanation of public key cryptography, he tricked the Computer Scientist into believing he describes some cryptography protocol, thus making him interested. Edheldil (talk) 10:22, 31 January 2014 (UTC)
By the way, what Cueball describes might very well be DNS cache poisoning -- or what NSA's supposed FOXACID servers do. Edheldil (talk) 10:31, 31 January 2014 (UTC)

I believe the essence of this story is in the encryption aspect, not the TCP. Many protocols feature a message-and-reply type of structure, it's not unique to TCP. The alternative to having CS reply to each phrase is to have him not reply to each phrase, which would be boring and not really indicate what's going on in CS's head. As some cryptography problems can be complex they are sometimes stated in "chunks" so people can follow along more easily (See the Description section of the link). In trying to follow what might be a complex problem sometimes people will acknowledge that they understand each part in turn - weather for their own benefit or that of the problem stater. Jarod997 (talk) 21:04, 29 January 2014 (UTC)

Found it: Bruce Schneier, a notable modern Cryptographer has published a number of cryptography books in which he routinely references characters such as Alice, Bob, and Eve. Jarod997 (talk)
Also: TCP/IP doesn't necessarily ack every packet, it can also ack multiple packets in one go. This allows for a much larger throughput as the latency per packet goes down to zero. Kaa-ching (talk) 09:33, 30 January 2014 (UTC)