Generate Psuedo-Random Data using ARC4 as a PRNG

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ActiveX for 32-bit and 64-bit Windows

This example demonstrates how to use the ARC4 stream encryption algorithm as a pseudo-random number generator (PRNG). This example generates the random data as hex encoded strings. The EncryptStringENC method can be replaced with EncryptBytes to generate random bytes.

<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
</head>
<body>
<%
set crypt = Server.CreateObject("Chilkat_9_5_0.Crypt2")

success = crypt.UnlockComponent("Anything for 30-day trial")
If (success <> 1) Then
    Response.Write "Crypt component unlock failed" & "<br>"

End If

crypt.CryptAlgorithm = "arc4"
crypt.KeyLength = 128

crypt.SetEncodedKey "000102030405060708090A0B0C0D0E0F","hex"

crypt.EncodingMode = "hex"

'  We will repeatedly feed these 8-bytes of data to
'  the ARC4 stream encryptor to generate our pseudo-random
'  sequence.

strData = "012345678"

'  Set FirstChunk to 1 to initialize the ARC4 PRNG with the key.
crypt.FirstChunk = 1
crypt.LastChunk = 0

encryptedText = crypt.EncryptStringENC(strData)
Response.Write encryptedText & "<br>"

'  Set FirstChunk to 0 to continue encrypting
'  without re-initializing the ARC4 PRNG
crypt.FirstChunk = 0

For i = 1 To 16
    '  Repeatedly encrypting the same 8 bytes of data
    '  produces then pseudo-random sequence.
    encryptedText = crypt.EncryptStringENC(strData)
    Response.Write encryptedText & "<br>"
Next
%>
</body>
</html>