[Cryptography] A two key file/program

Donald Eastlake d3e3e3 at gmail.com
Fri May 17 17:40:43 EDT 2019


On Fri, May 17, 2019 at 1:40 AM Allen Schaaf
<netsecurity at sound-by-design.com> wrote:
> Hi folks,
> I'm looking for a program or file system to run on Windows
> 7/8.1/10 to keep data protected that requires two separate keys
> used at the same time to open the file. It needs to be like the
> missile launching system that was created using two physical keys
> at the same time to prevent one crazy person from starting a war.

The case of splitting in two seems pretty trivial. Generate a random
quantity R the size of the key and bitwise xor it with the key K
producing R.xor.K. Give one person R and the other R.xor.K. Neither
reveals anything about K (except its size). You just xor these two
keys together to recover the original key that opens the file.

> The goal for the credit union is to encrypt login information
> used by the staff.
> Each of the staff has six or seven user names and passwords for
> various local and remote systems. The manager/CEO and assistant
> manager need to enable access to each account when either there
> is a potential problem or when they are not available. One
> example of this need is that US law requires each employee to
> take a minimum one week vacation so that any fraudulent behavior
> will be interrupted and also that the transaction they did can be
> audited without them overseeing the audit process.

I think it is a regulation, not a law, and for banks it is two weeks,
not one week...

 Donald E. Eastlake 3rd   +1-508-333-2270 (cell)
 1424 Pro Shop Court, Davenport, FL 33896 USA
 d3e3e3 at gmail.com

> ...
> Allen

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