java - Why does my encrypted string looks like consisting of only question marks?

Question

I'm encrypting a string in Java, and when I'm printing the encrypted data, I see only question marks.

As an example:

• Plain text: jjkkjlkljkj

• Encrypted text: ???????????

• After decrypting this text again, I'm getting jjkkjlkljkj again.

So it looks like the encryption worked right. But why can I see only question marks?

Answer 1

Yes, it's because you can't print the strings that are resulting from the encryption.

Note that saving the encrypted result in a string will possibly result in loss of the data, so don't do that. Take it as a byte array, and convert it to a displayable format, like Base64 or just simple Hex.