RC4

    private int i = 0;
    private int j = 0;
    private int[] Table;

    public HabboRC4() {
        Table = new int[0x0100];
    }

    public void init(final byte[] Key) {
        int k = Key.length;
        this.i = 0;

        while(this.i < 0x0100) {
            this.Table[this.i] = this.i;
            this.i++;
        }
        this.j = 0;
        this.i = 0;
        while (this.i < 0x0100)
        {
            this.j = (((this.j + this.Table[this.i]) + Key[(this.i % k)]) % 0x0100);
            this.mk(this.i, this.j);
            this.i++;
        };
        this.i = 0;
        this.j = 0;
    }

    public byte[] parse(final byte[] b) {
        int k;
        byte[] y = new byte[b.length];

        int position = 0;

        for(int a = 0; a < b.length; a++) {
           this.i = ((this.i + 1) % 0x0100);
           this.j = ((this.j + this.Table[this.i]) % 0x0100);
           this.mk(this.i, this.j);
           k = ((this.Table[this.i] + this.j) %  0x0100);
           y[position++] = ((byte)(this.Table[k] ^ b[a]));
        }
        return y;
    }

    private void mk (final int k, final int y) {
        int x = this.Table[k];
        this.Table[k] = this.Table[y];
        this.Table[y] = x;
    }