🚀 go-pugleaf

sandberg@carroll1.cc.edu (Brian R. Sandberg) writes:

>I am writing an application in MS-BASIC V7.1 which uses random access data
>files.  Here's the problem:  these files contain confidential information.
>Is there a way to keep people from reading (accessing) these files?

>--
>Brian Sandberg
>sandberg@carroll1.cc.edu

Brian:

I don't think the fact that the files are random access and from BASIC
is an important issue - any file that any program saves can be hacked.
The best you can do it somehow encrypt the data in the buffers before
you write (PUT) it. It can be as simple (subtract 20 from the ascii
value) or as complex (run a dod encryption scheme on the entire buffer),
but it is up to your code to do.

Good luck!

Miles

In <3302@carroll1.cc.edu> sandberg@carroll1.cc.edu (Brian R. Sandberg) writes:
>I am writing an application in MS-BASIC V7.1 which uses random access data
>files.  Here's the problem:  these files contain confidential information.
>Is there a way to keep people from reading (accessing) these files?

Someone else mentioned encrypting the data before saving it out to
disk.  This is a pretty good idea.  Another thing that you might want
to do that is fairly easy is to put at the beginning of the file ascii
text like the following: Only Authorized Personnel may access this
data file.^Z the ^Z would be a ctrl-Z.  You could write a similar
string in the header of your file in binary.  This way if someone
tried to simply TYPE out the file then all they get is your message.
DOS will see the ^Z and stop. You might want to throw in a few or a
LOT of ^G's depending on what your size constraints are and how
annoying you want to be.

Bryan.

/* === Bryan Nehl ========== kodiak@Kodiakpc.Manhattan.KS.US =========+
[            USDA-ARS-NPA-WERU          ][ bdn@chepil.weru.ksu.edu    ]
[     913.532.6233 or 913.532.6495      ][ kodiak@matt.ksu.ksu.edu    ]
+_______________ ...!rutgers!matt.ksu.ksu.edu!kodiak _______________ */

In article <18bn7qINNnet@matt.ksu.ksu.edu> kodiak@matt.ksu.ksu.edu (Bryan D. Nehl) writes:
>In <3302@carroll1.cc.edu> sandberg@carroll1.cc.edu (Brian R. Sandberg) writes:
>>I am writing an application in MS-BASIC V7.1 which uses random access data
>>files.  Here's the problem:  these files contain confidential information.
>>Is there a way to keep people from reading (accessing) these files?
>
>Someone else mentioned encrypting the data before saving it out to
>disk.  This is a pretty good idea.  Another thing that you might want
>to do that is fairly easy is to put at the beginning of the file ascii
>text like the following: Only Authorized Personnel may access this
>data file.^Z the ^Z would be a ctrl-Z.  You could write a similar
>string in the header of your file in binary.  This way if someone
>tried to simply TYPE out the file then all they get is your message.
>DOS will see the ^Z and stop. You might want to throw in a few or a
>LOT of ^G's depending on what your size constraints are and how
>annoying you want to be.
>
>Bryan.
>
>/* === Bryan Nehl ========== kodiak@Kodiakpc.Manhattan.KS.US =========+
>[            USDA-ARS-NPA-WERU          ][ bdn@chepil.weru.ksu.edu    ]
>[     913.532.6233 or 913.532.6495      ][ kodiak@matt.ksu.ksu.edu    ]
>+_______________ ...!rutgers!matt.ksu.ksu.edu!kodiak _______________ */

One other suggestion that would be a little easier to work with is
to use a simple encryption scheme like ANDing or ORing with a
rotating bit pattern and storing your data in this format. This way
you prevent easy access to your data from someone who can
disassemble your work or even snapshot it in memory, since you
decrypt on the fly. Yes, a smart cookie can figure it out in a
matter of time, but it sounds like you want to keep honest people
honest, and this method will keep the overly curious at bay.

Paul

-- 
--------------------------------------------------------------------
            Bureaucracy: noun, plural - Bureaucracies.
         The process of turning energy into solid waste.
---------------------------------------------------------------------

....or you might try a simple scheme that I used for password encryption.
Again, it's not the most secure but it will keep non programers out of your
business.  

Generate a random number that will be used to add the the ASCII code of
each individual letter.  The random number should be such that it kicks
each letter into the upper (non letter) range.  This random number can be
store at the begining of the file and is used as the decode key for the
rest of the file.  This way if you encode the same word or group of words
twice.....each copy if different.

I don't have a copy of the codes with me as I write but it makes you
encoded file look like garbage and can be done with only a few lines of
code.  My examples are off my machine at present but I'd be glad to post an
example if you like.  

-- 

Submitted for your approval.....
Jerry Greenwood                                                      N9NRG
grnwood@gagme.chi.il.us                                       312-545-2219

--