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BACKGROUND OF THE INVENTION
This invention relates to a method of controlling the copying of computer
software and more particularly, to such a method which allows an unlimited
number of backup copies of a program to be made for the same machine, but
selectively prevents the execution of such backup copies or the original
on other unauthorized machines.
In recent years, the sale and/or licensing of computer software has become
an established industry of it own. In this industry, more than any other,
the illegal copying of copyrighted works of authorship has robbed the
copyright owner of large amounts of revenue. The illegal copying has come
from many different segments of users and other sellers of computer
software. On one extreme, the organized pirate copies software and then
sells it at discount to potential purchasers from the true owner, in
effect, putting the developer of the copyrighted version of the software
out of business. On the other extreme, a rightful possessor of the
software may make a limited number of additional copies for use as backup
copies on the original computer, or, if authorized by the owner of the
software, for use on a home computer, or for use on a replacement or
additional computer used by the authorized user in the same office.
Between these two extremes, many rightful possessors of software may
merely give, or even lend the software to friends or others in the same
office.
In the first case, the copyright owner is generally unwilling to grant his
permission to the pirate. In the second case, however, the copyright owner
generally should have no objection to true backup copies being used, since
the user of the software has a legitimate right to make a backup copy of
the software for protection against the inadvertent destruction of the
original copy. On the other hand, the owner of the software copyright may
or may not be willing to allow the user to copy the software for use on
other computers, or the owner of the software copyright may be willing to
allow the copying of the software for use on other computers in the same
office for an additional fee.
Attempts to solve copying problems in the past have included various
techniques of copy protection. Common for most of these techniques is the
placing of code in the program which limits the number of executable
copies of a particular copy of software which can be made. However, as
soon as a new technique for copy protection is developed, it is quickly
broken by knowledgeable computer experts. These experts then market
programs which allow the so called copy-protected software to be copied at
will. In some situations, such copying may be approved by the owner, such
as, making backup copies, but in other situations, the copying may be
without the owner's approval, and hence illegal, such as the making copies
for friends. However, the copy protect schemes typically don't distinguish
between the allowable copying and the illegal copying. Even to the extent
that the copy protection schemes of the prior art have allowed the making
of a backup copy of the software, such schemes generally don't allow a
legitimate backup of the backup or multiple backups of the original for
execution on the same machine. Further, the copy protect schemes of the
prior art do not prevent the permitted backup copies to be given to a
friend for a disallowed use on a different machine.
One drawback of many copy protection schemes of the past is that problems
may occur after an authorized user copies the software into a hard disk,
or other type of permanent large memory associated with the machine. These
problems, as well as the protests of the user to the inconveniences and
inability to make sufficient legitimate copies, have led many software
vendors to discontinue the use of copy protection schemes. The result, of
course, is that many unauthorized copies of software are being made,
thereby causing the author of the program to lose rightful rewards for his
creative endeavors.
Another problem with the marketing of software has more recently appeared
as hardware technology has advanced to allow a local area networks of many
computers and other sophisticated communications between computers in
either the same general area or across country. One problem the software
industry is facing as a result of this new technology is that large
companies with many computers are demanding either site licenses or large
volume discounts. In either case, the price of the software is directly
tied to the number of copies and it, thus, becomes necessary for the
software owner, or licensed distributor, to keep track of the number of
copies of the software being made by or for the large customer. Further,
many of the same problems of unauthorized copies made for friends or for
machines beyond the site licensed still remain. Traditional copy
protection schemes offer no solution to these problems.
It would be preferable to utilize a copy control scheme, rather than the
copy protection, or prevention, schemes of the prior art in order to
overcome the above noted problems. A copy control scheme is one in which
the scheme does not interfere with the proper execution of the software on
an authorized machine, in which the rightful possessor of the software can
make as many backup copies as is desired, and in which the party charged
with authorizing copies, such as a copyright owner, is able to approve,
control and have knowledge of all copies made for additional machines. In
addition, such a scheme should allow any of the backup copies to be
executed on the authorized machine, but stop the execution of all such
backup, or other unauthorized, copies on machines other than the
authorized machine. Finally, such a scheme should be able to prevent
override techniques, such as those programs of the prior art that override
copy protection schemes, from avoiding, overriding or bypassing the copy
control scheme.
Another problem of the prior art has been the ability of authorized
distributors of software to assure the registration of licensed software
and obtain desired feedback from users regarding computer configurations.
Registration is desirable in the current environment of software marketing
using unsigned license agreements, since the registration of the software
with the authorized distributor may manifest the acceptance of the license
terms. Further, the system configuration feedback of the software
developer's customer base is valuable business information for the
developer so that the developer knows what additional functions can or
should be added to future enhancements of the software product, or what
customer segment should be targeted in a marketing program based on
hardware availability for future software products.
SUMMARY OF THE INVENTION
In accordance with one aspect of this invention, there is provided a method
of controlling the use of copies of computer software, which software
includes an application program for performing a desired task and an
associated a first control program. The first control program allows the
application program, and a copy made therefrom, to be executed on a given
machine, but prevents the application program, and all copies thereof,
from being executed on another machine. The method comprises the steps of
generating a configuration code related to the hardware of the given
machine and transmitting the configuration code to a remote machine. The
remote machine is programmed with a second control program related to the
first control program. Further, the method includes the steps of
generating, by the second control program, a permission code at the remote
machine related to the configuration code transmitted thereto,
transmitting the permission code to the given machine, and storing the
permission code as a part of the first control program to allow the
associated application program, or copies thereof, to be executed only on
the given machine.
BRIEF DESCRIPTION OF THE DRAWINGS
One preferred embodiment of the subject invention is hereafter described,
with reference being made to the following Figures, in which,
FIG. 1 shows a general system block diagram of apparatus used to perform
the software copy control method of the subject invention;
FIG. 2 shows an example of the configuration code generated at the user's
machine; and
FIG. 3 shows a flow diagram of the procedures in obtaining authorization to
use software subject to copy control on a given computer.
DESCRIPTION OF THE EMBODIMENT
Referring now to FIG. 1, a user computer system 10 and a central computer
system 12, located at a location remote from the user computer system 10,
are shown. A communications link 14 connects user computer system 10 with
central computer system 12. Communications link 14 may take the form of
either a direct processor to processor link, such as through modem 16 of
user computer 10 to an associated modem (not shown) included as a part of
computer 12, or an indirect link, such as through a conventional telephone
18. If an indirect link, such as telephone 18, is used, central computer
12 may communicate using a voice synthesizer prompter unit (not shown) and
a signal receiver unit (not shown) included therein responsive to
telephone tone signals.
User computer system 10 may be any conventional computer system, from the
smallest personal computer to the largest main frame system. For example,
system 10 may be a typical business personal computer system including a
hard disk drive 20, one or more diskette drives 22, a defined amount of
random access memory (RAM) 24, a microprocessor system (CPU) 26, one or
more input devices 28, such as a keyboard, and one or more output devices
30, such as a display or a printer. In a typical operating environment, an
application program is stored on either the disk associated with disk
drive 20, or on a diskette inserted into on of the diskette drives 22.
This program is then executed, on command of the user, that is, it is
copied into the RAM 24 and controls the tasks performed by CPU 26 to cause
a desired application to be performed.
One of the tasks that CPU 26 may be programmed to perform is to copy the
program stored on either the disk or the diskette associated with drives
20 or 22 onto another diskette. In the past, programmers have tried to
prevent this copying of the program code, as opposed to data generated by
using the program, by techniques generally known as copy protection
schemes. Briefly, copy protection schemes worked by preventing certain
critical code from being copied, or from being copied more than a certain
number of times, such as one or two. However, as soon as a programmer came
up with a particularly scheme for copy protection, another programmer was
able to come up with a scheme to override the protection scheme. One
problem with the conventional copy protection schemes is that the code
implementing the scheme is always the same for any given program. Thus, a
person desiring to break the code, only has to do it once for a given
program, and then all copies of the program can be copied.
The subject invention utilizes a different philosophy than has been used in
the past. Rather than placing copy preventing code on the media containing
the program, a footprint of the machine is taken and a control program
responding to only the footprint is placed within the application program
to allow that machine to make and use as many copies of the program as
desired. However, the control program prevents the application program
from being executed on a machine having a different footprint. Thus, a
person with the right to use the program is not be prevented from enjoying
the full use of his program on the approved machine, but such person is
not be able to make copies of the program for use on unapproved machines.
Controls are also included in the code to allow multiple machines to be
approved, or to allow changes to be made to the approved machine from time
to time, such as the addition of more memory to RAM 24.
In practice, the manner in which the invention is to be implemented is that
the first time the application program is used, a prompt appears on the
screen requiring the user to register the program for use on a defined
user computer 10 with the owner or the authorizing agent of the owner.
This prompt may include the serial number of the program and a
configuration code generated by the application program based on the
configuration of user machine 10.
The serial number of the program will have been previously assigned by the
licensor or seller of the program and may include information relating to
how many different machines have been authorized. For example, a serial
number may allow the application program to be copied into two hard disks
for execution on two different machines, or it may limit the copying to
only a single machine configuration. The price the user pays for this
privilege may be related to the number of machines upon which the
application program is to operate. Alternatively, a purchaser or licensee
of the application program may obtain a site license, allowing a certain
number of copies to be made and that certain number is included as a part
of the serial number. Further, in other situations, the software owner may
inventory programs in a central location of a customer and only bill for
the programs after distribution by the customer to its employees or other
users. The billing amount could, in turn, be related to the number of
programs actually in use.
The configuration code is generated after the program is loaded into the
machine is based on the particular hardware parameters of the machine. For
example, the configuration code may be a multi-digit number, in which each
group of one or more digits includes different hardware configuration
information. Further, special information, unique to a particular machine,
such as information unique to a disk, disk drive or RAM based on specific
tests, may also be included as a part of the configuration code.
The prompt screen informs the user starting to load the application program
for the first time to call a certain telephone number to obtain a
permission code to be entered into the user's computer 10. This call can
be made using the modem 16 or the telephone 18 and connects the user with
central computer 12. If the telephone 18 is used, computer 12 requests
that the serial number of the program be first entered using the keypad of
a tone generating telephone. Then, computer 12 requests that the
configuration code be entered in the same way. This can all be
accomplished by using a voice synthesizer as a part of computer 12, so
that no human labor is involved. If modem 16 is used, information can be
transmitted directly between the two computers 10 and 12 to obtain the
same information.
Once computer 12 has received the correct information, it can first check
to determine if another copy has been authorized for the particular serial
number. If such a copy is authorized, the records are updated for that
serial number. If no additional copies are permitted, a message so
indicating is generated and computer 12 disconnects the link.
After computer 12 determines that a copy can be made, it generates a
permission code based on the configuration code previously transmitted to
it. This configuration code may be based on an algorithm defined only by
the special, or configuration unique, code portion of the configuration
code. Once the permission code is generated, it is transmitted to the user
machine, either directly through modem 16, or to the operator of user
machine 10 over the telephone 18. At that point, the user enters the
permission code. The control program portion of the software then
recreates the generation of the permission code based on the hardware and
can compare the internally generated code to the entered permission code.
If the two codes compare, execution of the program is allowed; if the two
codes do not compare, then further execution of the application program is
stopped and a message is displayed indicating to the user that execution
on that machine has not been approved. This, of course, should only happen
if the configuration of the machine upon which execution is attempted is
not the same as the configuration of the machine which received the
original permission code.
In order to allow the owner of user machine 10 to upgrade computer 10, such
as by adding more memory to RAM 24 or adding or replacing diskette drives
22, artificial intelligence type of programming may be included as a part
of the control program to accept and remember normal type upgrades and
make appropriate modifications to the calculation and comparison scheme,
so that the modified configuration is still able to have the application
program executed thereon. Alternatively, when any change occurs, or when
certain types of changes occur, the owner of the application program may
desire that a new configuration code be generated and a new registration
and permission code generation and entry procedure occur. Such a decision
on the part of the application program owner is, in part at least, based
on the value of always knowing the exact hardware configuration of its
customer base.
Referring now to FIG. 2, an example of the configuration code is shown. In
this example, the code includes twelve digits, labeled for convenience 1-9
and A-C. Each of the digits may include any number 0-9 therein, and these
numbers may be encrypted, if desired. In the example chosen, the following
hardware elements are measured:
1. Total Number of Hard Drive Units
2. Hard Disk Partition Size
3. Free Space Percentage on Hard Disk
4. RAM memory size
5. Total Number of Disk Drives
6. Current Logged Disk Drive
7. Mode Number
The hardware data may be encoded into a twelve digit configuration code
number, as follows:
______________________________________
Digit Number Meaning
______________________________________
1 Number of Disk Drives
2 100's Digit of RAM size
3 1's Digit of Hard Disk Partition Size
4 Number of Hard Drives
5 Logged Drive Number
6 10's Digit of RAM Size
7 1's Digit of Mode Number
8 1's Digit of Free Space Percent
9 10's Digit of Hard Disk Size
A 1's Digit of RAM Size
B 10's Digit of Mode Number
C 10's Digit of Free Space Percent
______________________________________
The two digit Mode Number used in the configuration code may be a special
number calculated for a particular machine based on a unique configuration
footprint of the user's computer 10. For example, the Mode Number may be
determined by utilizing the fact that the oxide coating on all hard disks
is not perfectly uniform and further that the nonuniformity is different
from one computer to another computer. A special formatting utility
program, such as those used by the disk manufacturers for quality control,
can then be used to allow unstable bytes of information, as defined by the
special formatting program but not by normal commercial standards, found
in one or more sectors of the disk to be determined. Since the
nonuniformities on the disk or diskette remain constant with time, the
test is repeatable, since the special format program will arrive at the
same number each time it measures the same disk or diskette. Once the
number of unstable bytes is determined, that number can be reduced to the
two digit Mode Number by, for example, only using the two least
significant digits, or by summing the digits until a one or two digit
number is found. The Mode Number can further be modified so that it can
differentiate between soft disks, that is floppy disks or diskettes as
such are commonly called, or hard disks, by for instance reserving certain
numbers for each type or using even numbers for soft disks and odd numbers
for hard disks. The copy control scheme can then differentiate and use
different copy control procedures for software designed to be stored on
different types of media.
The remaining information relating to the hardware defined portions of the
configuration code are easily obtained by conventional techniques and can
be inserted into the configuration code in the proper position by the
control program portion of the software. It should be understood that the
configuration code may, if desired, be encrypted or compressed in any
conventional or proprietary manner. It is only necessary that a
corresponding second control program in central computer 12 is
correspondingly programmed to understand the configuration code. For
example, the Mode Number, as previously mentioned, may be any number
between 00 and 99 and this number is based on a physical measured
criteria, such as the number of unstable bytes found on a hard disk by
using a special formatting program. However, the Mode Number included in
the configuration code may be different than the number measured, due to
an encryption technique. For example, the Mode Number in the configuration
code may be determined by first adding a number found by multiplying the
sum of the first and last digits of the configuration code by three and
then adding that number to the measured value. Such addition could occur
either before or after the measured physical criteria number is reduced to
two digits. Further, the Mode Number may be forced to an even or odd
number if it is desirable to control the copying of soft and hard disks in
different manners.
Once the serial number and configuration code is communicated to central
computer 12 by either modem 16 or telephone 18, central computer 12
performs the necessary checks against the serial number and stores the
hardware configuration data in an appropriate data base. Then, central
computer 12 calculates the permission code based on the hardware
configuration information provided thereto. Central computer 12 has many
different algorithms it can use to calculate the permission code and the
particular one selected relates to the unique Mode Number portion of the
configuration code. For example, if the Mode Number is 75, then the
algorithm to calculate the permission code may be the sum of the RAM size
plus the hard disk size, times the percent of free space. For a different
Mode Number, a different algorithm using different portions of the
configuration code information is used to calculate the permission code.
After the permission code generated by computer 12 is returned to and
entered in user computer 10, user computer 10 is able to duplicate, with
the appropriate additional information that may be contained in the
permission code (or previously included in the control program) the
recalculation of a permission code based on retesting the hardware
configuration. As long as the recalculated permission code and the
originally entered permission code are the same, execution of the
application program on the user computer 10 is allowed to continue. This
is also be true for any backup copies of the application program which the
user desires to create, since the regeneration of the permission code
results in the same permission code as was originally entered.
However, if a person attempted to execute a copy of the software on another
machine, the attempt to recalculate the permission code would result in a
different permission code being recalculated. In this instance, the
control program associated with the application program would see
non-matching permission codes and would then prevent execution. However,
if the proprietor of the software had granted rights to run the software
on a second machine, a message could be placed on the screen advising the
user that the use on second machine must be registered. In such an
instance, the second machine user would communicate with central computer
12, as previously explained, and would receive a new, and different,
permission code based on the hardware configuration of the second machine.
However, where all of the allowed machines had previously been registered,
central computer 12 would immediately know this fact from checking its
data base information. In such an event, central computer 12 would
communicate back the message indicating that no additional machines had
been authorized. The customer could then obtain the additional
authorization by paying the required fee or use the software only on an
authorized machine, such as user computer 10.
Referring now to FIG. 3, a flow diagram of the procedure for initializing
the copy control scheme on a given item of software is shown. FIG. 3
includes blocks 40 through 56 (even numbers only). Beginning at block 40,
the diskette containing the application program and the control program is
inserted into the user's computer 10 and according to block 42, the
configuration code is calculated and displayed by the user's computer 10
along with the serial number of the program and a message instructing the
user to communicate with central computer 12. Other information regarding
the copy control scheme may also be conveyed, such as the general manner
in which the scheme operates to allow an unlimited number of backup copies
to be made for execution on the user's computer 10, but not for execution
on any other computer.
Next, according to block 44, the user communicates the serial number and
configuration code to central computer 12 using either modem 16 or
telephone 18, as previously explained. Additional information may also be
communicated at this point, such as the telephone number of the user or a
security code. Thereafter, according to block 46, central computer 12
checks its data base to be sure that a copy of the software is permitted.
If not, then according to block 48, central computer 12 informs the user
that no additional copies have been authorized and terminates the
communication link. If central computer concludes that another machine is
authorized to copy and execute the software, then, as indicated at block
50, central computer 12 stores the configuration data and updates its data
base for the transmitted serial number. Next, central computer 12
calculates the permission code from the information contained in the
transmitted configuration code and communicates the calculated permission
code back to the user over the communication link.
Thereafter, as indicated at block 52, the user enters the communicated
permission code for storage with and subsequent use by the software. The
subsequent use, as indicated at block 54, is the recalculation of a
permission code by user's computer 10 under the control of the software
and, as indicated at block 56, a comparison between the originally entered
permission code and the recalculated permission code occurs. The
recalculation may, in part, either include or be controlled by a unique
response to information communicated from central computer 12 as a part of
the original permission code. If the comparison is made, execution is
allowed to continue; however, if no comparison is found, execution is
stopped and an appropriate message is displayed informing the user that
authorization for that computer has not been granted. A reauthorization
procedure, beginning at block 40, may then be attempted and if use of the
software on additional machines is authorized, a new permission code for
the new machine will be given.
It should be noted that when the user computer 10 recalculates the
permission code at block 56, the recalculation is based on both the
hardware configuration and the original permission code. In order to allow
the user to upgrade computer 10, artificial intelligence may be included
in the software to note and remember certain types of upgrades which occur
and to modify the original permission code based on such modifications.
However, certain modifications, such as those which affect the hardware
from which the Mode Number was derived, may result in a new registration
procedure being required.
Many additional safeguards can be placed in the system to prevent attempts
to override the copy control system. For example, the communication
between the user and central computer could include the user's telephone
number, which number could be checked by computer 12 redialing that number
to again contact the user, or to see if a busy signal were received or to
make the user give a security code after the redial. If it turned out that
an unauthorized copy of the software were at that telephone number, then
the location of unauthorized software could be determined. Other
safeguards can include dispersing the control program throughout the
application program and using techniques which would cause the control
program to self destruct itself or the application program if attempts to
modify, or even print, the control program were made. This would prevent,
or greatly inhibit any attempts to override the copy control scheme of the
subject invention in the manner that the copy protect schemes of the prior
art have been overridden.
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