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Cuchulainn
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sha1

April 30th, 2014, 7:53 pm

QuoteOriginally posted by: outrunQuoteOriginally posted by: CuchulainnFound thisQuoteMain difference between SHA1, SHA1CryptoServiceProvider, SHA1Managed and SHA1Cng are:1) SHA1: this is abstract class. All other implementation of SHA1 (SHA1CryptoServiceProvider, SHA1Managed and SHA1Cng) implements this abstract class. To create concreate SHA1 class, use SHA1.Create(). By default SHA1.Create() returns SHA1CryptoServiceProvider, which is configurable.To configure default SHA1 implementation: http://msdn.microsoft.com/en-us/library/693aff9y.aspx2) SHA1CryptoServiceProvider: this is wrapper for unmanaged CryptoAPI(CAPI). This is Federal Information Processing Standard (FIPS) certified.3) SHA1Managed: this is complete implementation of SHA1 using managed code. This is fully managed but not FIPS certified and may be slower.4) SHA1Cng: this is wrapper for unmanaged Cryptography Next Generation (CNG). These are newer implementation of cryptographic algorithms by Microsoft with Windows 2008/Windows Vista or newer. This is also FIPS certified. That's a IMO too much terminology and wrappers for a realy simple function. You know I'm not a big fan of verbose OO design structures.But I'm not experienced .NET, it looks like it all has to do mainly with managed/unmanaged versions?Yes, it's overkill. But .NET has to talk to native by a wrapper unless it's in C# which would be too slow.
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dd3
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May 1st, 2014, 8:04 am

QuoteOriginally posted by: rmaxIt was electromechanical and worked on a set of rotors that rotated once each time a key was hit. There was also a "plug board" for additional configuration operations. Turing realised that he could subtract the operations of the plugboard by reflecting the signals back through the plugboard configuration, thus cancelling out their effect. This meant that Bletchley Park only had to workout the combination of the rotors (initially 3 but this was increased to 5 later in the war). Turing is always hailed (rightly) as the genius behind enigma, but there were some other brilliant minds that were excellent at lateral thinking.Flaw in the Engima Code:
 
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Cuchulainn
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sha1

May 1st, 2014, 8:27 am

QuoteOriginally posted by: dd3QuoteOriginally posted by: rmaxIt was electromechanical and worked on a set of rotors that rotated once each time a key was hit. There was also a "plug board" for additional configuration operations. Turing realised that he could subtract the operations of the plugboard by reflecting the signals back through the plugboard configuration, thus cancelling out their effect. This meant that Bletchley Park only had to workout the combination of the rotors (initially 3 but this was increased to 5 later in the war). Turing is always hailed (rightly) as the genius behind enigma, but there were some other brilliant minds that were excellent at lateral thinking.Flaw in the Engima Code: talk. So, not having a fixed point was an Achilles' Heel?
Last edited by Cuchulainn on April 30th, 2014, 10:00 pm, edited 1 time in total.
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Traden4Alpha
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sha1

May 1st, 2014, 12:55 pm

QuoteOriginally posted by: CuchulainnQuoteOriginally posted by: dd3QuoteOriginally posted by: rmaxIt was electromechanical and worked on a set of rotors that rotated once each time a key was hit. There was also a "plug board" for additional configuration operations. Turing realised that he could subtract the operations of the plugboard by reflecting the signals back through the plugboard configuration, thus cancelling out their effect. This meant that Bletchley Park only had to workout the combination of the rotors (initially 3 but this was increased to 5 later in the war). Turing is always hailed (rightly) as the genius behind enigma, but there were some other brilliant minds that were excellent at lateral thinking.Flaw in the Engima Code: talk. So, not having a fixed point was an Achilles' Heel?Wouldn't the flaw be that the rotor mechanism implemented both the forward and backward transform in one device?All encryption functions need to be 1-to-1 and onto so that any possible message can be encrypted and no two messages map to the same encrypted message. But that does not imply that the decryption function is a trivial WRT the encryption function.
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