Looking for Hash Function MD5.

Dear All

i am looking for a hash function , that i can implement it for encryption and decryption process.

as two parties can code the message and decode it.

thanks

[Walter Roberson]

You know that hash functions are for authentication and not for encryption? One researcher did come up with an interesting technique, named something like "Wheat and Chaff" that used only authentication to carry secret messages, but it required sending 50+ variations on every packet with the idea being that you would not know which one of them was the right packet unless you had the correct authentication key.

Answer 1

[Jan]

• In Matlab (which calls Java internally): Fex: DataHash
• Faster in C-Mex: Fex: CalcMD5

The latter is updated in a few days by a remarkably faster version. I'm going to post the new link here.

Btw. Did you try to ask your favorite internet search engine for "MD5 Matlab"?

[Haitham]

thanks mate , my project in matlab. checked the first link but i am getting some errors while running the code it self.

[Jan]

You get some errors? This is strange, because Matlab should stop after the first error. So please post the error message and the command you have used.

--- Ah, I see, you've written a comment in the FileExchange. Please post the complete message here. The actual problem has been cut away.

[Haitham]

DataHash(1, 1) Undefined function 'Error_L' for input arguments of type 'char'.

Error in DataHash (line 145) Error_L('BadInput2', '2nd input [Opt] must be a struct.');

[Haitham]

i tried everything just to run it , EDU>> DataHash(1, HEX) different versions but i get same error undefined function.

[Walter Roberson]

DataHash(1, struct('Format', 'HEX'))

[Jan]

@Haitham: If you get the error message "Undefined function 'Error_L'", the file DataHash.m has been damaged. In the correct M-file you find the definition of this function in the line 464:

function Error_L(ID, varargin)

I suggest to follow these steps:

• Download the ZIP file again
• Extract the file DataHash.m to a user-defined folder of your Matlab path
• Try the examples by typing this in the command line:

DataHash([])
Opt.Format = 'Hex'
DataHash(1, Opt)

Does this run?

I'm going to simplify the input, such that strings like 'HEX' are expected directly without the need to create a struct. But in your case the problem is not the input, but that the subfunction Error_L has been lost, edited away or hidden by commenting, or whatever.