Generate Psuedo-Random Data using ARC4 as a PRNG

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. Note: This example uses new features available in the pre-release, or any official new version released after 17-October-2007.

Download Chilkat Ruby Library

require 'chilkat'

crypt = Chilkat::CkCrypt2.new()

success = crypt.UnlockComponent("Anything for 30-day trial")
if (success != true)
    print "Crypt component unlock failed" + "\n"
    exit
end

crypt.put_CryptAlgorithm("arc4")
crypt.put_KeyLength(128)

crypt.SetEncodedKey("000102030405060708090A0B0C0D0E0F","hex")

crypt.put_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 true to initialize the ARC4 PRNG with the key.
crypt.put_FirstChunk(true)
crypt.put_LastChunk(false)

encryptedText = crypt.encryptStringENC(strData)
print encryptedText + "\n";

#  Set FirstChunk to false to continue encrypting
#  without re-initializing the ARC4 PRNG
crypt.put_FirstChunk(false)

for i in 1 .. 15
    #  Repeatedly encrypting the same 8 bytes of data
    #  produces then pseudo-random sequence.
    encryptedText = crypt.encryptStringENC(strData)
    print encryptedText + "\n";
end