Difference between revisions of "Obfuscation"

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(A page on obfuscating Haskell code)
 
(Found results for 1993 bottomth hocc)
Line 4: Line 4:
 
obfuscation. There have been three Haskell obfuscation contests:
 
obfuscation. There have been three Haskell obfuscation contests:
   
* Pred Zeroth (early 1990s?)
 
  +
* [http://www.haskell.org/pipermail/haskell/2004-August/014387.html Bottomth Obfuscation Haskell Contest]
* [http://www.scannedinavian.org/iohcc/zeroth-2003/ Zeroth Haskell Obfuscation Contest]
+
* [http://www.scannedinavian.org/iohcc/zeroth-2003/ 2003 Zeroth Obfuscated Haskell Contest]
* [http://www.scannedinavian.org/iohcc/succzeroth-2004/ Succ Zeroth International Obfuscated Haskell Code Contest]
+
* [http://www.scannedinavian.org/iohcc/succzeroth-2004/ 2004 Succ Zeroth Obfuscated Haskell Contest]
   
 
The ability to use symbols for identifiers helps a lot of course, as
 
The ability to use symbols for identifiers helps a lot of course, as
 
does suspending the use of layout. Point-free style is also an excellent
 
does suspending the use of layout. Point-free style is also an excellent
help. Finally, Haskell's clean semantics makes refactoring code
 
  +
help. Use of strange monads and type trickery can all be very confusing.
 
Finally, Haskell's clean semantics makes refactoring code
 
(semi-)mechanical, leading to some interesting obfuscated encodings (one
 
(semi-)mechanical, leading to some interesting obfuscated encodings (one
 
can rewrite all keywords with lambda abstractions for example).
 
can rewrite all keywords with lambda abstractions for example).

Revision as of 09:02, 16 February 2006

Obfuscation

Haskell is (perhaps surprisingly) an excellent language for code obfuscation. There have been three Haskell obfuscation contests:

 * Bottomth Obfuscation Haskell Contest
 * 2003 Zeroth Obfuscated Haskell Contest
 * 2004 Succ Zeroth Obfuscated Haskell Contest

The ability to use symbols for identifiers helps a lot of course, as does suspending the use of layout. Point-free style is also an excellent help. Use of strange monads and type trickery can all be very confusing. Finally, Haskell's clean semantics makes refactoring code (semi-)mechanical, leading to some interesting obfuscated encodings (one can rewrite all keywords with lambda abstractions for example).

Example

The following illustrates how, by turning off layout, rewriting keywords (let, case, where) as lambdas, and using symbols for identifiers (in this case multiple '?' characters), Haskell may be highly obfuscated.

--------------------------------------------
module Main where{import List;import System;
import Data.HashTable as H;(???????)=(concat
);(??????)(???)(????)=((groupBy)(???)(????))
;(??????????????????????)(????)=((??????????
)((tail).(???????))((????????????????????)((
??????)(?????????????????????)(????))));(??)
=([' ']);(??????????????)=((hashString));(?)
=((>>=));(???????????????????????)([((???)),
(????)])=((?????????????)(???))?(\(?????)->(
(????????????????)(==)(??????????????))?(\((
???))->((??????????????????)(???????????????
)(???)(?????))>>((?????????????????)(???))?(
\((?????))->((((???????????????????)((????))
((??????????????????????))((?????))))))));((
???????????????????????))(??)=(????????????)
("usage f dic out");(?????????????????????)(
(???),(??????))((????),(????????????????????
))=((???)==(????));(?????????????????)(???)=
(toList)(???);(????????????????????)(????)=(
((??????????)(((??????????)(snd)))((????))))
;(??????????????????)(???????????????)(???)(
(?????))=(((mapM)(((???????????????)(???)))(
(lines)(?????))));(???????????????????)(????
)(???????????????????????)(?????)=(?????????
)(????)((unlines)((???????????????????????)(
?????)));(????????????????)(???)((????))=(((
new)(???)(????)));(main)=((???????????)?(((\
(???)->((???????????????????????)(???))))));
(???????????????)(???)(????)=((????????)(???
)((sort)(????))((??)++(????)));(???????????)
=(getArgs);(????????????)(???)=((((print))((
???))));(??????????)(???)(????)=(((map)(???)
(????)));(????????)((???))(????)(?????)=((((
H.insert))((???))(????)(?????)));(?????????)
((???))((????))=(((writeFile)(???)((????))))
;(?????????????)(???)=(((readFile)((???))))}
--------------------------------------------