Java

public static String CellKeysGeneration() {

        byte[] btba = new byte[5];

        Random r = new Random();

        r.nextBytes(btba);

        for (int i = 0; i < btba.length; i++) {

            btba[i] = btba[i];

        }
        String str = tohexString(btba);
        return str;
    }

    public static String tohexString(byte[] bytes) {

        StringBuffer sb = new StringBuffer(bytes.length * 2);

        for (int i = 0; i < bytes.length; i++) {
            sb.append(tohex(bytes[i] >> 4));
            sb.append(tohex(bytes[i]));

        }

        return sb.toString();

    }

    public static char tohex(int nibble) {

        final char[] hexdigit = { '0', '1', '2', '3', '4', '5', '6', '7', '8',
                '9', 'A', 'B', 'C', 'D', 'E' , 'F' };

        return hexdigit[nibble & 0xF];
    }