Re: Ada News Brief - 96-05-24.txt [1/1]

[dewar@cs.nyu.edu (Robert Dewar)]

I find the claim that JBC is easier to reverse engineer than machine
code unsupportable from a technical point of view. JBC is just machine
code for a virtual machine. It is true this is a higher level machine
code, which makes a difference, but that difference can be in either
direction. Sometimes the encoding of stuff at a high level can be
harder to disentangle. For example, access types in an Ada source
program get translated to Java classes. Is it really true that this
makes algorithms that at a conceptual level use pointers easier to
understand by reverse engineering -- I think not.

At least it is now clear what Richard is concerned with (the mention of
reverse engineering was not in his original note), but it is also pretty
clear that this his opinion is borrowed from others rather than based on
technical analysis, and I suspect that the opinion, as stated in the trade
press, may also be based on a general theory that interpretors are easier
to reverse engineer.

I am unconvinced, though to be fair, you really would have to try doing
some reverse engineering to be sure. I think what you would find out is
that some programs are far easier than others to reverse engineer, and
these fundamental differences (having to do with how involved the
algorithms are, and how extensively the code is optimized, etc.) will
be much more significant than any minor difference caused by different
machine models.

Finally, it is important to emphasize that this has *nothing at all* to
do with the Java language, but rather with the specific delivery methods,
i.e Richard's comments about reverse engineering apply to Ada or any
other language converted to JBC, and do not apply to Java programs that
are compiled into hard machine code.