(Delphi ActiveX) ARC4 Encryption (ARCFOUR)

ARC4 (ARCFOUR) encryption. The Chilkat encryption component supports the ARC4 streaming encryption algorithm.

Chilkat for Delphi Downloads Chilkat ActiveX DLL for Delphi Chilkat non-ActiveX DLL for Delphi * The examples here use the ActiveX DLL.

uses
    Winapi.Windows, Winapi.Messages, System.SysUtils, System.Variants, System.Classes, Vcl.Graphics,
    Vcl.Controls, Vcl.Forms, Vcl.Dialogs, Vcl.StdCtrls, Chilkat_TLB;

...

procedure TForm1.Button1Click(Sender: TObject);
var
crypt: TChilkatCrypt2;
keyHex: WideString;
encStr: WideString;
decStr: WideString;

begin
// This example assumes the Chilkat API to have been previously unlocked.
// See Global Unlock Sample for sample code.

crypt := TChilkatCrypt2.Create(Self);

// Set the encryption algorithm = "arc4"	
crypt.CryptAlgorithm := 'arc4';

// KeyLength may range from 1 byte to 256 bytes.
// (i.e. 8 bits to 2048 bits)
// ARC4 key sizes are typically in the range of 
// 40 to 128 bits.
// The KeyLength property is specified in bits:
crypt.KeyLength := 128;

// Note: The PaddingScheme and CipherMode properties
// do not apply w/ ARC4.  ARC4 does not encrypt in blocks --
// it is a streaming encryption algorithm. The number of output bytes
// is exactly equal to the number of input bytes.

// EncodingMode specifies the encoding of the output for
// encryption, and the input for decryption.
// It may be "hex", "url", "base64", or "quoted-printable".
crypt.EncodingMode := 'hex';

// Note: ARC4 does not utilize initialization vectors.  IV's only
// apply to block encryption algorithms.  

// The secret key must equal the size of the key.
// For 128-bit encryption, the binary secret key is 16 bytes.
keyHex := '000102030405060708090A0B0C0D0E0F101112131415161718191A1B1C1D1E1F';
crypt.SetEncodedKey(keyHex,'hex');

// Encrypt a string...
// The output length is exactly equal to the input.  In this
// example, the input string is 44 chars (ANSI bytes) so the
// output is 44 bytes -- and when hex encoded results in an
// 88-char string (2 chars per byte for the hex encoding).
encStr := crypt.EncryptStringENC('The quick brown fox jumps over the lazy dog.');
Memo1.Lines.Add(encStr);

// Now decrypt:
decStr := crypt.DecryptStringENC(encStr);
Memo1.Lines.Add(decStr);
end;