Found
static byte[] convert(String string)
and
static String convert(byte[] bytes)
ineffictive.
Need I suggest some solutions (like Apache Commons

)?
Those convert methods also bothered me at first look, but I decided to leave it for later if they need optimizing. My girlfriend promised to buy me a license for YourKit (hey, they have a sale now, personal license is only $99 instead of $500) and I will spend some time profiling. It is only worth optimizing things that really are measured to be a problem.