ROT Encryption

[CrashX]

ROT Encryption( http://en.wikipedia.org/wiki/ROT13 ) done using wxWidgets.

Code:

Code: Select all

wxString RotEncryption( const wxString & pStr, int pLowerLimit, int pUpperLimit )
{
	int offset = (pUpperLimit-pLowerLimit)/2+((pUpperLimit-pLowerLimit)%2);
	wxString encrypted = pStr;
	wxChar data;
	for(unsigned int i=0; i < pStr.length(); i++)
	{
		data = pStr.GetChar(i);
		if((data >= pLowerLimit) && (data <= pUpperLimit ))
		{
			if( ( data > ( pUpperLimit - offset ))
			 || ( data < ( pLowerLimit - offset )) )
			{
				data = data - offset;
			} else
			{
				data = data + offset;
			}
		} 
		encrypted.SetChar(i,data);
	}
	return encrypted;
}

Usage:

Code: Select all

wxString encrypted = RotEncryption(RotEncryption(_T("Welcome to wxWidgets!"),32,(1<<(8*sizeof(wxChar)-1))-1),-1<<((8*sizeof(wxChar))-1),-1);
	wxString decrypted = RotEncryption(RotEncryption(encrypted,-1<<((8*sizeof(wxChar))-1),-1),32,(1<<(8*sizeof(wxChar)-1))-1);

Notes:
- Lower and Upper value can't be both odd or even.
- The above example uses range NEGETIVE_MAX_CHAR to -1 and 32 to POSITIVE_MAX_CHAR to do encryption.

[priyank_bolia]

But why you want to use such easy to break encryption, why not wx3DES, etc.

[CrashX]

Well if you keep running this function with different ranges then it becomes a bit more difficult to break.

Where can I download wx3DES ? Source Code ?

[priyank_bolia]

wxTripleDES from http://priyank.co.in
You need to register first before downloading.

and wxDES is available directly also from Carlos Dominguez. I don't have the link now.

[phlox81]

Take a look at Crypto++, its one of the best encryption libraries for c++.
http://www.cryptopp.com/

[upCASE]

Well if you keep running this function with different ranges then it becomes a bit more difficult to break.

Sorry, but this is not quite correct. using different ranges won't make it harder to break or more secure. In fact it won't change a thing if I already guessed that it might be a kind of ROT algorithm.

Where can I download wx3DES ? Source Code?

Most algorithm that are considered to be "secure" have free implementations flying around. Crypto++ is quite good, openssl has many encryption modules available as well.