Android characters encoding vs Java Characters encoding

In Android I have a text string that I read (its bytes) in this way:

String b = "7af18klmo02";
byte[] b=udid.getBytes("UTF-8");

After this, I encrypt the string using a Public Key in this way:

c = Cipher.getInstance("RSA/ECB/NoPadding");
c.init(Cipher.ENCRYPT_MODE, pubKeyNew);
encodeFile = c.doFinal(b);

After this, I try to print out the "encryption result" on the console in this way:

String criptato = null;
 try {
        criptato = new String(encodeFile, "UTF8");          
    } catch (UnsupportedEncodingException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    }

    System.out.println("ENCRYPTED STRING: "+criptato);
    System.out.println("LENGTH: "+criptato.length());

What I obtain is:

ENCRYPTED STRING: (unreproducible characters)
LENGTH: 244

There are a lot of unreadable characters in the output console. I did not intend to change them, and I think there is some particular encoding I should use to avoid this.

But when I send the encrypted string using a NDEF message throught NFC I obtain a different "string" on Java side that I'm not able to understand:

\x12\t\xc7NL\xb9\xee\xb3\xae\xe4\xa5\xe5\x88\x93\xd6\\=S\xff\xa0'\xf1\xd0\x87\x8bF\xb0\x0cT!\xd6\xca0\x8b\xe5\x13\xfd\x85\xc3=Z,u1\x14}d\x0b5\xe7\x0bBY\xe7$\xee\xc0Z\x150;r\xfa\xce\x93\x90\x0b\xdas\xe6o\xe8\x954._\x93\xa4\xc2\x06\xe3\x84\xf5\xdbw\x91\xd4'%\xf71\xf3B\x9eA=f\r\xaeu\xe5m\x1en\xdaw\x12\xad+\xfe\xb2\x91;\xbe\t\x1dTd\xf5m\t2\xafl<v\xf0\x06\x98)2]\xbeV\x86\xa7\xe7\xe6\xc3\x1f*b\x8c&\xd8ho\x18\x8a;\x8f\x8cW\xb6\x88A\xc9`^\xc2>\xfcQ\x07\x86\xb3\x82\x16\x8b\xed?\xae\xb0\x9bT<\x84y4/\xef\xf9j\xf2\xff\x17\x8d\xfddQN\x84\x97\xf2z\x88RJtw\xe2F5\xcd=l`\x89\xeaN\x86a\xde\xa4\xdb\xb1\x15x\xe4\xf0.\x06\x03\x16|\xfee\xbf\x8a\x81_\x86\xbc\x83\xd9 \xbc;\x16V.]\xb4\xf9\t>?{\xcdF\xa8\x82\x08\xe0\\L

LENGTH: 700

I am running under Ubuntu 13.04

Is this ISO 8859-15 encoding or what?

Why final length is 700 instead of original 244?

How can I convert these characters in UTF-8 so that i can decrypt them to obtain my original string?

Any help is much appreciated.