Hiding code from intruders, a different slant on an old question

[Littlefield, Tyler]

On 10/7/2015 5:38 AM, cl at isbd.net wrote:
> I know questions similar to this are often asked but my reasons for
> wanting to do this (and thus ways it can be done) are slightly different.
>
> I have a number of little utility scripts (python and others) which I
> use to automate the process of decrypting and displaying things like
> files containing passwords.  
>
> The encryption I use is reasonably secure anyway but I'd like to hide
> the programs/methods I use so that:-
>
> 1 - The encrypted files are not identifiable as encrypted data (the file
> command just returns 'data' so they can't be identified by that).  If
> there's a script in my ~/bin directory that relates directly to the
> files it's obvious they're encrypted.
>
> 2 - The method used for encryption isn't obvious, again an obvious
> script will show the program I have used.
>

You have two options here:
1) Use a strong encryption like aes256 etc and don't bother trying to
"hide" the code because it's just a blob of data and they'll not crack it.
2) Encrypt the whole drive if you use something like *nix/*bsd.
The only thing hiding the code will do is make them guess at the method.
But if you use a good method in the firstplace, you shouldn't have any
issues because it's not going to be cracked.

> I *could* write a C program which just exec()'s the required programs,
> if they're done separately this would be fairly well hidden but I was
> wondering if there's anything more obvious I can do that enables me to
> do things easily in Python.
>
>
> This is for protecting against any possible intruder who has gained
> access to my system by breaking an ssh password or stealing my laptop
> for example.  It's *not* for hiding code that I'm giving to others,
> I'd be quite happy to give the code in question to people who might
> want to use it.
>


-- 
Take care,
Ty
http://tds-solutions.net
He that will not reason is a bigot; he that cannot reason is a fool; he that dares not reason is a slave.