MASTER SOFTWARE CORPORATION 59 DeGarmo Hills Road Wappingers Falls, NY 12590 QUALITY SOFTWARE SINCE 1958

1. CHOOSING A CRYPTOGRAPHIC PRODUCT



     Master Software offers six separate cryptographic products.  All of
them are strong, all of them are reliable, all are easy to use, all of them
are well-suited to their tasks.  How do you choose?



TABLE OF CONTENTS


1. CHOOSING A CRYPTOGRAPHIC PRODUCT
  1.1. Messages and Files
  1.2. Distributed Keys
  1.3. No Distributed Keys
  1.4. Authentication
  1.5. Time-Proven Methods
  1.6. Less Typing



1.1. Messages and Files


     The first question is, what are you trying to protect?  Are you
protecting files on a single computer or within a local network, or are you
protecting messages which will be sent over public networks such as the
Internet?

     If you need to protect files on your computer, then GK-Crypt is the
right choice.  It is easy to use, reasonably fast, and extremely secure.
In fact, it is the strongest file encryption product available outside of
the military.  It is stronger than many of the encryption products used by
foreign governments, and far stronger than the encryption used by banks,
credit card companies, brokerages and similar businesses.

     If, on the other hand, you need to protect messages, we offer a choice
of five products, NK-Crypt, N2-Crypt, N3-Crypt, NS-Crypt and OP-Crypt.  The
one you choose depends on your setup.



1.2. Distributed Keys


     If the people or groups who need to communicate secretly are already
in contact, already known to one another, then OP-Crypt is the logical
choice.  This is especially true if you already have a communications
network set up, and you already have an established method for distributing
secret encryption keys.

     OP-Crypt is the only cryptographic product, from any source, which can
be considered absolutely secure.  It uses the renowned One-Time Pad
encryption algorithm, the only algorithm that has ever been proven to be
unbreakable.  Provided that the keys are never revealed, your messages will
remain secure and unbreakable forever.

     OP-Crypt is fast and easy to use.  Its great advantage over all of the
competing products is that there is no need to distribute keys for each
message.  The OP-Crypt package generates long, secure message keys.  Only
the secret network key and station keys need to be distributed, which needs
to be done only once for each station.



1.3. No Distributed Keys


     If you need to protect messages, but you do not know beforehand who
will be communicating, if you do not have a method for distributing keys,
if people frequently join your network with no previous contact with your
headquarters, or if you expect that people already in the field may need to
communicate directly with each other, then NK-Crypt, N2-Crypt, N3-Crypt and
NS-Crypt are your best choices.  In fact, they are your only choices.
There are no other products available anywhere that can establish secure
communications without any exchange of keys.

     NK-Crypt is based on large prime numbers.  This is a technology that
has stood the test of time.  (The patent for the algorithm underlying
NK-Crypt expired in 1993.)  Hundreds of mathematicians have tried and
failed to break it.  However, it is slow, and unsuited for sending long
messages or large files.

     N2-Crypt, N3-Crypt and NS-Crypt all offer the advantage of speed.

     N2-Crypt is  500 times as fast as GK-Crypt.
     N3-Crypt is 1200 times as fast as GK-Crypt.
     NS-Crypt is 2200 times as fast as GK-Crypt.

N2-Crypt, N3-Crypt and NS-Crypt are all based on our exclusive matrix
technology.  This method is so new and revolutionary that Master Software
has been granted four US patents on our matrix encryption algorithms.

     N2-Crypt and N3-Crypt use single-sided matrix methods, while NS-Crypt
uses a more advanced double-sided matrix algorithm.  Master Software has
full confidence in the strength of these methods.  We have performed
extensive analysis of potential attacks.  Over time we expect users of the
old NK-Crypt to migrate to the newer, speedier N2-Crypt, N3-Crypt or
NS-Crypt.



1.4. Authentication


     When encryption is used to protect communications there are two types
of threats, passive threats and active threats.  The typical passive threat
is wire-tapping, where an opponent obtains your messages, but does not add,
delete or change your messages.  All of Master Software's message
encryption products provide strong security against these passive threats.
Normally, an eavesdropper will not change your message traffic, in order to
stay undetected.

     The typical active threat is impersonation, where an opponent poses as
a legitimate user in order to receive messages or to send bogus messages.
When there is a danger of impersonation, the legitimate users need to use
message authentication in order to assure that they are communicating only
with other authorized users.

     The products NK-Crypt, N2-Crypt and N3-Crypt provide customized
versions where the users of the customized version can communicate only
with users having that same version.  Users of the standard version, or
users of a different customized version, cannot communicate with the users
of your customized version.

     Master Software provides secure distribution of these customized
versions.  User groups can set up any desired arrangement so that only
authorized users can purchase a given customized version.  Each customized
version has a name, and the organization can choose to have a password
which must be provided by anyone ordering their custom version.  Other
identifying methods can also be used.  For example, an organization could
require that orders for their customized version be placed only on the
company letterhead, and paid by company checks.

     Nonetheless, some organizations may not wish Master Software to have
access to their customized version.

     NS-Crypt Version 02 provides authentication in a different way.
NS-Crypt allows users to choose their own secret authentication key,
unknown to anyone else.  Any group that wishes to provide message
authentication this way should use NS-Crypt Version 02.



1.5. Time-Proven Methods


     Users who demand time-proven security can use any of GK-Crypt,
OP-Crypt and NK-Crypt with full confidence.  They are designed using
cryptographic techniques that have proven reliable over decades, even
centuries of use.

     Users who want the latest cutting-edge products may choose GK-Crypt
and NS-Crypt.  NS-Crypt uses an entirely new technology for which four US
patents have been granted.  GK-Crypt uses standard cryptographic methods
combined in a powerful innovative way where they strengthen and reinforce
each other to repel every known type of attack.



1.6. Less Typing


     All of these formidable cryptographic techniques have been built into
program packages designed for ease of use.  The most important factor is
that users do not need to memorize and type large numbers of keys.  All of
the products have Master Keys which must be entered when the package is
started.  For GK-Crypt, NK-Crypt, N2-Crypt, N3-Crypt and NS-Crypt the
Master Key is the only key that ever needs to be typed.

     OP-Crypt, however has a network key, which is typed once when the
software is installed, and station keys which need to be securely
distributed, and typed when new stations join the network.  Thus, for
actively growing networks, there is ongoing key maintenance.