[Intermediate] Creating a picture cipher

[InfamousNoone]

This cipher relies on the 'hybrid cipher' which can be found here;



Include the library (dll) attached as a reference to a .NET project and then add "using PictureCryptLibrary;" or whatever it is to use a namespace in the .NET language of your choice.

// enc
PictureCrypt.Encrypt(encfile, outputfile, cipherkey);

// dec
PictureCrypt.Decrypt(decfile, outputfile, cipherkey);

The .exe included is a program that already implements the crypto, just simply drag an drop picture(s) onto the .exe and it'll walk you through the process

Sorry about the source it's messy, but I wasn't really going for speed while I coded this (not visibility)

        static void Encrypt(string In, string Out, byte Key)
        {
            HybridCipher cipher = new HybridCipher(Key);
            Bitmap bmp = new Bitmap(In);
            byte[] buffer = new byte[bmp.Height * bmp.Width * 4];
            uint offset = 0;
            fixed (byte* lpBuffer = buffer)
            {
                for (int x = 0; x < bmp.Width; x++)
                {
                    for (int y = 0; y < bmp.Height; y++)
                    {
                        *((uint*)(lpBuffer + offset)) = (uint)bmp.GetPixel(x, y).ToArgb();
                        offset += 4;
                    }
                }
            }

            byte[] chunk = new byte[100];
            offset = 0;
            for (int i = 0; i < buffer.Length / 100; i++)
            {
                Array.Copy(buffer, i * 100, chunk, 0, 100);
                chunk = cipher.Encrypt(chunk);
                Array.Copy(chunk, 0, buffer, i * 100, 100);
            }

            offset = 0;
            Bitmap bmp2 = new Bitmap(bmp.Width, bmp.Height);
            fixed (byte* lpBuffer = buffer)
            {
                for (int x = 0; x < bmp2.Width; x++)
                {
                    for (int y = 0; y < bmp.Height; y++)
                    {
                        bmp2.SetPixel(x, y, Color.FromArgb(*((int*)(lpBuffer + offset))));
                        offset += 4;
                    }
                }
            }
            bmp2.Save(Out);
        }

        static void Decrypt(string In, string Out, byte Key)
        {
            HybridCipher cipher = new HybridCipher(Key);
            Bitmap bmp = new Bitmap(In);
            byte[] buffer = new byte[bmp.Height * bmp.Width * 4];
            uint offset = 0;
            fixed (byte* lpBuffer = buffer)
            {
                for (int x = 0; x < bmp.Width; x++)
                {
                    for (int y = 0; y < bmp.Height; y++)
                    {
                        *((uint*)(lpBuffer + offset)) = (uint)bmp.GetPixel(x, y).ToArgb();
                        offset += 4;
                    }
                }
            }

            byte[] chunk = new byte[100];
            offset = 0;
            for (int i = 0; i < buffer.Length / 100; i++)
            {
                Array.Copy(buffer, i * 100, chunk, 0, 100);
                chunk = cipher.Decrypt(chunk);
                Array.Copy(chunk, 0, buffer, i * 100, 100);
            }

            offset = 0;
            Bitmap bmp2 = new Bitmap(bmp.Width, bmp.Height);
            fixed (byte* lpBuffer = buffer)
            {
                for (int x = 0; x < bmp2.Width; x++)
                {
                    for (int y = 0; y < bmp.Height; y++)
                    {
                        bmp2.SetPixel(x, y, Color.FromArgb(*((int*)(lpBuffer + offset))));
                        offset += 4;
                    }
                }
            }
            bmp2.Save(Out);
        }