It's RC4 stream cipher implementation which outputs the same format results as in the article http://en.wikipedia.org/wiki/RC4#Test_vectors

RC4

import java.io.UnsupportedEncodingException;
import java.nio.charset.Charset;

import org.apache.commons.codec.DecoderException;
import org.apache.commons.codec.binary.Hex;

public class RC4 {
	private int[] S = new int[256];
	private final int keylen;

	public RC4(final byte[] key) {
		if (key.length < 1 || key.length > 256) {
			throw new IllegalArgumentException("key must be between 1 and 256 bytes");
		} else {
			keylen = key.length;
			for (int i = 0; i < 256; i++) {
				S[i] = i;
			}

			int j = 0;

			for (int i = 0; i < 256; i++) {
				j = (j + S[i] + key[i % keylen]) % 256;
				int temp = S[i];
				S[i] = S[j];
				S[j] = temp;
			}
		}
	}

	public String encrypt(final String message) {
		byte[] plaintext = new byte[0];
		try {
			plaintext = message.getBytes("ASCII");
		} catch (UnsupportedEncodingException e) {
		}

		byte[] ciphertext = toBytes(transform(toInts(plaintext)));
		return Hex.encodeHexString(ciphertext);
	}

	private int[] transform(final int[] input) {
		final int[] output = new int[input.length];

		final int[] S = new int[this.S.length];
		System.arraycopy(this.S, 0, S, 0, S.length);

		int i = 0, j = 0, k, t;
		for (int counter = 0; counter < input.length; counter++) {
			i = (i + 1) & 0xFF;
			j = (j + S[i]) & 0xFF;
			S[i] ^= S[j];
			S[j] ^= S[i];
			S[i] ^= S[j];
			t = (S[i] + S[j]) & 0xFF;
			k = S[t];
			output[counter] = input[counter] ^ k;
		}

		return output;
	}

	private int[] toInts(byte[] bytes) {
		int[] output = new int[bytes.length];
		for (int i = 0; i < bytes.length; i++) {
			output[i] = bytes[i];
		}
		return output;
	}

	private byte[] toBytes(int[] ints) {
		byte[] output = new byte[ints.length];
		for (int i = 0; i < ints.length; i++) {
			output[i] = (byte) ints[i];
		}
		return output;
	}

	public String decrypt(final String ciphertext) {
		try {
			int[] cipherints = toInts(Hex.decodeHex(ciphertext.toCharArray()));
			for (int i = 0; i < cipherints.length; i++) {
				cipherints[i] = cipherints[i] & 0xff;
			}
			byte[] plaintext = toBytes(transform(cipherints));
			return new String(plaintext, Charset.forName("ASCII"));
		} catch (DecoderException e) {
		}
		return null;
	}

	public static void main(String[] args) {
		byte[] key = "Key".getBytes();
		RC4 rc4 = new RC4(key);
		String message = "pedia";
		System.out.println("Message: " + message);
		String cipherText = rc4.encrypt(message);
		System.out.println("Encrypted: " + cipherText);
		String decrypted = rc4.decrypt(cipherText);
		System.out.print("Decrypted: " + decrypted);
	}
}