explain xkcd - User contributions [en]

Talk:1287: Puzzle

2013-11-06T19:06:00Z

Clwhisk:

So is there an answer to the puzzle? [[User:Clwhisk|Clwhisk]] ([[User talk:Clwhisk|talk]]) 19:06, 6 November 2013 (UTC)

Black thinks he's playing Go and white thinks he's playing chess. Although a 7 x 7 board is a bit small for go, it is not unusual for a beginner to play on such a board {{unsigned|hax}}

It is a 9x9 go board! (usually used for learning, as its smaller, less strategic, and quicker to finish game, whereas regular go is played on 19x19 intersections). Olivier.

::You beat me to it. "Less strategic" also means "more tactical". In my experience, 9x9 boards are rare (mostly, people would just use part of a 19x19 board), but when they do exist, they have 4 handicap intersections marked with dots. [[User:Homunq|Homunq]] ([[User talk:Homunq|talk]]) 08:28, 6 November 2013 (UTC)

::: 9x9 boards are great for variety and getting through games, and for beginners of all levels! Go on a 9x9 is about as hard as chess, in terms of playability, state space, and only recently seeing pro strength computers. [[User:Clwhisk|Clwhisk]] ([[User talk:Clwhisk|talk]]) 18:59, 6 November 2013 (UTC)

The picture on xkcd.com is changed. The bishop on e4 is removed and the one on c1 moved to d2. [[Special:Contributions/141.101.93.11|141.101.93.11]] 08:48, 6 November 2013 (UTC)

Would it be better to use algebraic notation instead, seeing as FIDE stopped recognizing descriptive notation in 1981? {{unsigned|Banak}}

::Possibly - I was trying to distinguish between Go moves and Chess moves by using the older Chess notation as a disambiguation, but... eh. I'm ambinotational - I read metric and imperial and barely notice the conversion. :) [[User:SleekWeasel|SleekWeasel]] ([[User talk:SleekWeasel|talk]]) 11:18, 6 November 2013 (UTC)
:::Then you may have a career at NASA ahead of you... ;) [[Special:Contributions/141.101.98.214|141.101.98.214]] 14:26, 6 November 2013 (UTC)

It would be helpful to give a description - or at least a primer (or a link to one) - of the notation used for chess moves (i.e. Q, N, R ... x, +, #, ... which sides of the board are alphabetic vs. which are numeric). [[Special:Contributions/108.162.221.228|108.162.221.228]] 16:55, 6 November 2013 (UTC)

Talk:1287: Puzzle

2013-11-06T19:05:24Z

Clwhisk:

So is there an answer to the puzzle?

Black thinks he's playing Go and white thinks he's playing chess. Although a 7 x 7 board is a bit small for go, it is not unusual for a beginner to play on such a board {{unsigned|hax}}

It is a 9x9 go board! (usually used for learning, as its smaller, less strategic, and quicker to finish game, whereas regular go is played on 19x19 intersections). Olivier.

::You beat me to it. "Less strategic" also means "more tactical". In my experience, 9x9 boards are rare (mostly, people would just use part of a 19x19 board), but when they do exist, they have 4 handicap intersections marked with dots. [[User:Homunq|Homunq]] ([[User talk:Homunq|talk]]) 08:28, 6 November 2013 (UTC)

::: 9x9 boards are great for variety and getting through games, and for beginners of all levels! Go on a 9x9 is about as hard as chess, in terms of playability, state space, and only recently seeing pro strength computers. [[User:Clwhisk|Clwhisk]] ([[User talk:Clwhisk|talk]]) 18:59, 6 November 2013 (UTC)

The picture on xkcd.com is changed. The bishop on e4 is removed and the one on c1 moved to d2. [[Special:Contributions/141.101.93.11|141.101.93.11]] 08:48, 6 November 2013 (UTC)

Would it be better to use algebraic notation instead, seeing as FIDE stopped recognizing descriptive notation in 1981? {{unsigned|Banak}}

::Possibly - I was trying to distinguish between Go moves and Chess moves by using the older Chess notation as a disambiguation, but... eh. I'm ambinotational - I read metric and imperial and barely notice the conversion. :) [[User:SleekWeasel|SleekWeasel]] ([[User talk:SleekWeasel|talk]]) 11:18, 6 November 2013 (UTC)
:::Then you may have a career at NASA ahead of you... ;) [[Special:Contributions/141.101.98.214|141.101.98.214]] 14:26, 6 November 2013 (UTC)

It would be helpful to give a description - or at least a primer (or a link to one) - of the notation used for chess moves (i.e. Q, N, R ... x, +, #, ... which sides of the board are alphabetic vs. which are numeric). [[Special:Contributions/108.162.221.228|108.162.221.228]] 16:55, 6 November 2013 (UTC)

Talk:1287: Puzzle

2013-11-06T18:59:45Z

Clwhisk:

Black thinks he's playing Go and white thinks he's playing chess. Although a 7 x 7 board is a bit small for go, it is not unusual for a beginner to play on such a board {{unsigned|hax}}

It is a 9x9 go board! (usually used for learning, as its smaller, less strategic, and quicker to finish game, whereas regular go is played on 19x19 intersections). Olivier.

::You beat me to it. "Less strategic" also means "more tactical". In my experience, 9x9 boards are rare (mostly, people would just use part of a 19x19 board), but when they do exist, they have 4 handicap intersections marked with dots. [[User:Homunq|Homunq]] ([[User talk:Homunq|talk]]) 08:28, 6 November 2013 (UTC)

::: 9x9 boards are great for variety and getting through games, and for beginners of all levels! Go on a 9x9 is about as hard as chess, in terms of playability, state space, and only recently seeing pro strength computers. [[User:Clwhisk|Clwhisk]] ([[User talk:Clwhisk|talk]]) 18:59, 6 November 2013 (UTC)

The picture on xkcd.com is changed. The bishop on e4 is removed and the one on c1 moved to d2. [[Special:Contributions/141.101.93.11|141.101.93.11]] 08:48, 6 November 2013 (UTC)

Would it be better to use algebraic notation instead, seeing as FIDE stopped recognizing descriptive notation in 1981? {{unsigned|Banak}}

::Possibly - I was trying to distinguish between Go moves and Chess moves by using the older Chess notation as a disambiguation, but... eh. I'm ambinotational - I read metric and imperial and barely notice the conversion. :) [[User:SleekWeasel|SleekWeasel]] ([[User talk:SleekWeasel|talk]]) 11:18, 6 November 2013 (UTC)
:::Then you may have a career at NASA ahead of you... ;) [[Special:Contributions/141.101.98.214|141.101.98.214]] 14:26, 6 November 2013 (UTC)

It would be helpful to give a description - or at least a primer (or a link to one) - of the notation used for chess moves (i.e. Q, N, R ... x, +, #, ... which sides of the board are alphabetic vs. which are numeric). [[Special:Contributions/108.162.221.228|108.162.221.228]] 16:55, 6 November 2013 (UTC)

Talk:1287: Puzzle

2013-11-06T18:59:28Z

Clwhisk:

Black thinks he's playing Go and white thinks he's playing chess. Although a 7 x 7 board is a bit small for go, it is not unusual for a beginner to play on such a board {{unsigned|hax}}

It is a 9x9 go board! (usually used for learning, as its smaller, less strategic, and quicker to finish game, whereas regular go is played on 19x19 intersections). Olivier.

::You beat me to it. "Less strategic" also means "more tactical". In my experience, 9x9 boards are rare (mostly, people would just use part of a 19x19 board), but when they do exist, they have 4 handicap intersections marked with dots. [[User:Homunq|Homunq]] ([[User talk:Homunq|talk]]) 08:28, 6 November 2013 (UTC)

::: 9x9 boards are great for variety and getting through games, and for beginners of all levels! Go on a 9x9 is about as hard as chess, in terms of playability, state space, and only recently seeing pro strength computers.

The picture on xkcd.com is changed. The bishop on e4 is removed and the one on c1 moved to d2. [[Special:Contributions/141.101.93.11|141.101.93.11]] 08:48, 6 November 2013 (UTC)

Would it be better to use algebraic notation instead, seeing as FIDE stopped recognizing descriptive notation in 1981? {{unsigned|Banak}}

::Possibly - I was trying to distinguish between Go moves and Chess moves by using the older Chess notation as a disambiguation, but... eh. I'm ambinotational - I read metric and imperial and barely notice the conversion. :) [[User:SleekWeasel|SleekWeasel]] ([[User talk:SleekWeasel|talk]]) 11:18, 6 November 2013 (UTC)
:::Then you may have a career at NASA ahead of you... ;) [[Special:Contributions/141.101.98.214|141.101.98.214]] 14:26, 6 November 2013 (UTC)

It would be helpful to give a description - or at least a primer (or a link to one) - of the notation used for chess moves (i.e. Q, N, R ... x, +, #, ... which sides of the board are alphabetic vs. which are numeric). [[Special:Contributions/108.162.221.228|108.162.221.228]] 16:55, 6 November 2013 (UTC)

1286: Encryptic

2013-11-04T18:29:40Z

Clwhisk: somewhat cryptic title

{{comic
| number = 1286
| date = November 4, 2013
| title = Encryptic
| image = encryptic.png
| titletext = It was bound to happen eventually. This data theft will enable almost limitless [xkcd.com/792]-style password reuse attacks in the coming weeks. There's only one group that comes out of this looking smart: Everyone who pirated Photoshop.
}}

==Explanation==
{{w|Triple DES}} is an older but still relatively secure encryption algorithm that works on 64-bit (8 character) blocks. Assuming that the passwords are stored in plain ASCII, this means that each sequence of 8 characters on the same position is always encrypted to the same result and therefore two passwords starting with “12345678” would start with the same block after being encrypted. Furthermore, this means that you can actually get a very good idea of the length of the password since anything with only one block is a password with length between 1 and 8 characters, with two blocks it has between 9 and 16 characters etc.

This way of storing passwords does not follow the recommended way of using a suitable cryptographically-secure {{w|Hash function|hash function}} that yields only a single block so that there is no way to tell the length of the password from the result. It is also a good practice to {{w|Salt (cryptography)|add a salt}} specific to each user (like their username) so that two users with the same password would not have the same hash.

Adobe also stored hints users created for their passwords. That means that an attacker knows not only if the same 8 characters are used for multiple passwords but also has some hints for guessing them. That means that common password portions should be easy to recover and that any user may be “compromised” by someone else using a part of the same password and providing a good hint. As an example, a password having three hints “Big Apple”, “Twin Towers” and “If you can make it there” is probably “New York”. The weakness here is that no decryption and therefore no hard cracking has to take place, you just group the passwords by their encrypted blocks and try to solve them like a crossword puzzle.

It seems the examples are not taken from the actual leaked file as that [http://arstechnica.com/security/2013/11/how-an-epic-blunder-by-adobe-could-strengthen-hand-of-password-crackers/ uses a different format].

The title text makes a reference to [[792|Black Hat’s trouble with what to do with stolen passwords]]. It also states that users of pirated Photoshop are the winners here. This is because in order to make Photoshop pirate-able, it was modified (cracked) by removing the requirement for registration so their passwords were not sent to Adobe and therefore are not present in the leaked file.

The title itself is a reference to [http://en.wikipedia.org/wiki/Cryptic_crossword cryptic crosswords]

==Passwords==
{|
! align="left"| Encryption
! Hint
! Password
|-
|4e18acc1ab27a2d6
|weather vane sword
|
|-
|4e18acc1ab27a2d6
|
|
|-
|4e18acc1ab27a2d6 a0a2876eb1ea1fea
|name1
|
|-
|8babb6299e06eb6d
|duh
|password
|-
|8babb6299e06eb6d a0a2876eb1ea1fea
|
|password1
|-
|8babb6299e06eb6d 85e9da81a8a78adc
|57
|password57
|-
|4e18acc1ab27a2d6
|favorite of 12 apostles
|
|-
|1ab29ae86da6e5ca 7a2d6a0a2876eb1e
|with your own hand you have done all this
|Judith1510
|-
|a1f9b2b6299e7a2b eadec1e6ab797397
|sexy earlobes
|charlie sheen
|-
|a1f9b2b6299e7a2b 617ab0277727ad85
|best tos episode
|charlie x
|-
|39738b7adb0b8af7 617ab0277727ad85
|sugarland
|houstontx
|-
|1ab29ae86da6e5ca
|name + jersey#
|Judith15
|-
|877ab7889d3862b1
|alpha
|abc123
|-
|877ab7889d3862b1
|
|abc123
|-
|877ab7889d3862b1
|
|abc123
|-
|877ab7889d3862b1
|Michael Jackson
|abc123
|-
|38a7c9279cadeb44 9dca1d79d4dec6d5
|
|monster mash
|-
|38a7c9279cadeb44 9dca1d79d4dec6d5
|he did the MASH, he did the
|monster mash
|-
|38a7c9279cadeb44
|Purloined
|monster
|-
|a8ae5754a2b7af7a 9dca1d79d4dec6d5
|fav water-3 pokemon
|
|-
|}

==Transcript==
:Hackers recently leaked '''''153 million''''' Adobe user emails, encrypted passwords, and password hints.
:Adobe encrypted the passwords improperly, misusing block-mode 3DES. The result is something wonderful:

<pre>
User password Hint
------------- ----

4e18acc1ab27a2d6 weather vane sword
4e18acc1ab27a2d6
4e18acc1ab27a2d6 a0a2876eb1ea1fea name1
8babb6299e06eb6d duh
8babb6299e06eb6d a0a2876eb1ea1fea
8babb6299e06eb6d 85e9da81a8a78adc 57
4e18acc1ab27a2d6 favorite of 12 apostles
1ab29ae86da6e5ca 7a2d6a0a2876eb1e with your own hand you
have done all this
a1f9b2b6299e7a2b eadec1e6ab797397 sexy earlobes
a1f9b2b6299e7a2b 617ab0277727ad85 best tos episode
39738b7adb0b8af7 617ab0277727ad85 sugarland
1ab29ae86da6e5ca name + jersey#
877ab7889d3862b1 alpha
877ab7889d3862b1
877ab7889d3862b1
877ab7889d3862b1 obvious
877ab7889d3862b1 Michael Jackson
38a7c9279cadeb44 9dca1d79d4dec6d5
38a7c9279cadeb44 9dca1d79d4dec6d5 he did the MASH, he did the
38a7c9279cadeb44 Purloined
a8ae5754a2b7af7a 9dca1d79d4dec6d5 fav water-3 pokemon
</pre>

:The greatest crossword puzzle in the history of the world

{{comic discussion}}

[[Category:Comics with color]]