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Looking for an encryption-/decryption-algorithm which produces short output

Hi,

I have to find a symmetric encryption-decryption algorithm, which produces short output-data. I used the following code:

String ENCRYPTION_ALGORITHM = "PBEWithMD5AndDES";
       String pwd = "password";
       PBEParameterSpec PBE_PARAMETER_SPEC =
       new PBEParameterSpec(new byte[] { (byte)0x01, (byte)0x23, (byte)0x45, (byte)0x67,
       (byte)0x89, (byte)0xab, (byte)0xcd, (byte)0xef}, 1024);
       if( pwd != null ) {
       // yes -> fetch the encryption stream
       Cipher pbe;
       try {
       PBEKeySpec pbeKeySpec = new PBEKeySpec(pwd.toCharArray());
       SecretKeyFactory keyFactory = SecretKeyFactory.getInstance(
       ENCRYPTION_ALGORITHM);
       SecretKey pbeKey = keyFactory.generateSecret(pbeKeySpec);
       pbe = Cipher.getInstance(ENCRYPTION_ALGORITHM);
       pbe.init(Cipher.ENCRYPT_MODE, pbeKey, PBE_PARAMETER_SPEC);
       }
       catch (Exception e) {
       throw new PdiRuntimeException(e);
       }
       ByteArrayOutputStream bufOut = new ByteArrayOutputStream();
       bufOut.write("Das wird anders werden".getBytes());
       CipherOutputStream encrOut = new CipherOutputStream(bufOut, pbe);
       String s = new BASE64Encoder().encode( bufOut.toByteArray() );
       System.out.println( s );

       bufOut.reset();
       bufOut.write("419".getBytes());
       encrOut = new CipherOutputStream(bufOut, pbe);
       s = new BASE64Encoder().encode( bufOut.toByteArray() );
       System.out.println( s );

       bufOut.reset();
       bufOut.write("4198721987".getBytes());
       encrOut = new CipherOutputStream(bufOut, pbe);
       s = new BASE64Encoder().encode( bufOut.toByteArray() );
       System.out.println( s );
       }

and got - as I can see - always the next 2^n-character-length. One might say, that´s o.k., to get out of "4198721987", which is 10 characters, a return-value of 16 characters; but in fact "4198721987" is stored as an integer or long-value, so it is something like 4 characters and shouldn´t return such a long output.

Any hint, where I can find a good algorithm with less waste of bytes?

mnrz

you should not store the output as Integer.
it is wrong,besides, the base 64 encoding will return a string.

spetrowitsch

ASKER

I wanted to say: The value, which I want to encrypt (and later decrypt) is in most cases an integer or long, and shouldn´t result in such long encrypted return-values.

ASKER CERTIFIED SOLUTION

mnrz

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