Hardware mechanism for computer software security

Nestable software license authentication keys connect end-to-end on a circuit board to form an authentication key assembly for internal computer installation or for use as an external assembly connecting to a host system. The circuit board includes at least one plastic housing for one or more authentication keys which define a male connector at one end and a female connector at the opposite end, which connect to a female phone jack(s) electrically connected to the circuit board and attached to the end of a compression spring mounted within each housing. The spring(s) compresses as additional keys are connected end-to-end on the board and the spring biases the keys against the end of the circuit board. The authentication key assemblies may utilize a variety of circuit boards with a variety of connectors, and the external assembly is encased in the plastic housing for use with portable and Apple-type computers.

FIELD OF THE INVENTION 
The present invention relates to security devices for ensuring compliance 
with computer software licenses. Specifically, the invention relates to 
nestable hardware "keys" which connect end-to-end and attach to an 
internal or external expansion board or other adapter for mounting an 
entire chain of such keys. 
BACKGROUND OF THE INVENTION 
Security devices for protecting computer software are well known in the 
prior art. One such device, generally known as a "key" or dongle, is 
provided with some licensed computer software to prevent software piracy. 
The key is an I/O device which attaches to the parallel port, serial port, 
or small computer system interface (SCSI) port of a computer and includes 
a memory circuit with a stored, encrypted algorithm, such as a password or 
serial number. During initial installation of the protected program, the 
encrypted password is stored as a boot patch within the computer. The 
stored password, perhaps a serial number, looks for an associated password 
during each supported program initialization process to ascertain whether 
the correct key is attached properly to the computer system. 
Initialization of the program is disallowed unless the key password is 
compared and found to be associated with the stored password. 
A number of drawbacks and limitations exist while using current "keys". 
First, keys generally are installed in the first parallel port, LPT 1, 
which typically is used for installation and operation of printers and 
other peripherals. Keys frequently interfere with the use of printers by 
causing the host computer to receive a busy signal when addressing LPT1. 
Additionally, keys are a nuisance because they generally are installed 
externally and extend outward from LPT 1. Such external installation is 
cumbersome and prevents, for all practical purposes, installation of more 
than one key at a time. Increased concerns with ensuring compliance with 
software licensing has lead to the need to install more than one key. 
A heretofore unmet need exists for a method and apparatus enabling internal 
mounting of multiple, nestable keys, or secure external mounting of such 
keys, without interfering with operation of LPT1 for other operations, 
particularly printing operations. 
SUMMARY OF THE INVENTION WITH OBJECTS 
A nestable key and key mounting mechanism includes a key housing defining a 
multi-contact receptacle on one end thereof in communication with a 
multi-contact plug on the opposite end thereof to allow daisy chain 
connection of keys. One or more keys, connected end-to-end, are installed 
into a guide which attaches to a circuit board adapted to serve as a 
housing for the key(s) and an external or internal interface with the 
computer microprocessor using, for example, LPT3. The guide mechanism is 
one or more non-conductive tubes each having a tensioning device for 
biasing the position of the nestable keys towards the connection end of 
the board. A plurality of interconnected or individual non-conductive 
tubes each surrounding a tensioning device may be used, particularly for 
internally mounted circuit boards, and the board may be surrounded with a 
plastic case, or other non-conductive case, for external circuit boards. 
The specially configured board also serves as an interface between the 
computer central processing unit (CPU) and the authentication software 
located within the key. 
A general object of the invention is to provide an authentication key which 
overcomes the drawbacks and limitations of the prior art. 
A specific object of the invention is to provide a nestable authentication 
key and mounting mechanism to enable internal or external installation of 
one or more keys connected end-to-end. 
Another specific object of the invention is to provide a mounting apparatus 
for keys, including a circuit board configured with one or more tensioning 
devices, such as compressible springs, for biasing the position of keys 
towards the end of the circuit board. 
Yet another specific object of the invention is to provide an external 
housing for a circuit board designed to mount one or more authentication 
keys in a daisy chain arrangement thereon. 
A further object of the present invention is to provide a security device 
which interfaces to a computer system without interfering with print 
processes or operation of other peripherals. 
These and other objects, advantages and features of the present invention 
will become more apparent upon considering the following detailed 
description of preferred embodiments, presented in conjunction with the 
accompanying drawings.

DESCRIPTION OF PREFERRED EMBODIMENTS 
An adapter housing and authentication key assembly are shown generally in 
FIGS. 1 and 2 as reference number 20. Referring now to FIGS. 1-6, the 
assembly 20 defines key mounting apparatus including a circuit board 30, 
in the example shown an 8 bit COM/LPT edge connector interface board, 
which also serves as an interface between the computer microprocessor, 
using an LPT port, and an authentication key. While the LPT port is a 
preferred interface in at least some embodiments of the invention, in 
other embodiments any available parallel, serial, or other port may be 
used, including shared ports. The board 30 enables connection of the 
authentication key(s) to either the COM port or to the LPT port using 
cables 19 which connect to LPT jack 22. Alternatively, conventional RS-232 
cables may be provided to connect the board 30 to the microprocessor. 
The circuit board 30 preferably is modified by providing a generally 
rectangular cut out area 24 surrounded on both long sides by circuit board 
mounting walls 26. Mounting holes 29 are provided in the walls 26 for 
mounting one or more housings 28. The housings 28 are preferably made from 
plastic, although other non-conductive materials may be used. The housing 
28 shown as an example in FIGS. 1-6 defines a unitary top wall 32, paired 
side walls 34, a bottom wall (not shown), and a front wall 31 defining 
mounting openings 33. Mounting flanges 35 having apertures 37 therethrough 
allow the housings 28 to be attached to circuit board mounting walls 26 by 
placing screws 39 through mounting holes 29. 
As best shown in FIGS. 2 and 4, the housing 28 further defines eight, 
parallel interior guide walls 36 thereby forming four, enclosed guide 
tubes 38. The guide tubes 38 of the housings 28 form protective 
receptacles for surrounding one or more authentication keys. 
The housing 28 shown in FIGS. 1-6 is presented as an example only and may 
be modified so that the housing side walls 34 form the two outside guide 
walls 36 of the four guide tubes 38 thereby reducing the number of 
interior guide walls 36 to six. Additionally, the housing 28 may be molded 
so that the guide tubes 38 are four separate tubes interconnected by 
contiguous bottom walls therebetween. 
As best shown in FIG. 1, the front wall 31 of the housing 28 is secured 
against a back plate 21 the circuit board 30 when the housing 28 is 
attached to the circuit board 30. The back plate 21 is used to secure the 
board 30 within an expansion slot of the computer CPU. Mounting openings 
23 are provided in the back plate 21 for access therethrough to mating 
mounting openings 33 in the front wall 31 of the housing 28. A mechanical 
back stop 40 extends from one guide wall 36 of each of the guide tubes 38 
to retain authentication keys within the openings 23, 33 in, respectively, 
the back plate 21 and the end wall 31. 
At least one tensioning device 42, such as a compressible spring, is 
mounted to the board 30 by inserting the tensioning device 42 into a guide 
tube 38. Four springs 42, one in each guide tube, are shown as the 
tensioning devices in FIGS. 2-5. A conventional female phone connector 
jack 44, which is electrically connected to circuit board 30, is 
positioned at the end of each spring 42. The connector jacks 44 may or may 
not be attached to the end of the springs 42. 
One end of an authentication key 50 is attached to each female phone 
connector jack 44. Compression of the springs 42 allows additional keys 50 
to be mounted to the board 30 by connecting the keys 50 end-to-end and 
inserting the connected keys 50 within guide tubes 38 of the housing 28. 
The guide tubes 38 of the housing 28, together with the resistance 
provided by the tensioning device 42, maintains alignment of the connected 
jacks 44 and the keys 50 as the spring 42 biases the key 50 towards the 
end of the board 30. 
Each key 50 defines a male connector end 52 and a female connector end 54 
to enable interconnection of keys 50 in a daisy chain arrangement. The 
male connector end 52 of the first key 50, inserted within a guide tube 38 
for attachment to the board 30, attaches to the female phone connector 
jack 44. A second key is connected to the first key 50 by inserting the 
male connector 52 of the second key into the female connector end 54 of 
the first key. The connectors 54 may be, for example, four pin, six pin, 
or eight pin phone connectors. The keys 50 further define a housing 56 for 
a conventional authentication chipset 60. Connectors 52 are operatively 
connected to connectors 54 in a pass through arrangement. 
A second aspect of the present invention is shown in FIGS. 7A, 7B and 8 as 
reference number 200. FIG. 7A shows an authentication key assembly 200 
utilizing for a key mounting apparatus a conventional 8-bit bus RS-232 
expansion board 300 which may add an LPT port, or may be used in place of 
an LPT port, and occupies a single expansion slot in a CPU. An RS-232 jack 
220 is provided for cables 330 from the jack 220 to the motherboard of the 
microprocessor. 
The authentication key assembly 200 includes a generally rectangular, 
plastic guide tube 380 housing a spring 420 to which is attached a DB-9 or 
DB-25 female connector 440 defining a cable end having a 9 or 25 pin 
female D-shell. The female connector 440 is electrically connected by 
cables 330 to the RS-232 jack 220. The female connector 440 defines a key 
connecting end 442 having a pair of flanges 444 which extend from and are 
wider than the width of the upper portion of the plastic guide tube 380. 
One or more external, conventional keys 500, as described above for 
interfacing with an LPT port, may be attached end-to-end with the first 
key 500 connected to connector 440. The key(s) 500 are tensioned by the 
spring 420 and held in position on the board 300 within the guide tube 380 
by a back stop 400 at a single opening 446 through back plate 210. The 
plastic guide tube 380 defines a lower, outer portion 280 extending from 
and integral with the upper portion of the guide tube 380. The outer 
portion 280 is shaped to define a channel, or tensioner guide 460, to 
align the key(s)500 during insertion to secure the key(s) 500 within the 
channel 460 which serves as a lock support track. Up to four keys 500 may 
be installed on the board 300 in this aspect of the invention. 
A third aspect of the present invention is shown in FIGS. 9A, 9B, and 10, 
utilizing, as in the FIG. 7A embodiment, a conventional 8-bit RS-232 LPT 
expansion board 300 for mounting one or more conventional DB-9 
authentication keys 5000. A DB-9 RS-232 female connector 440 is provided 
at the end of each of three springs 420, and each connector 440 is 
connected by RS-232 cables 330 to an RS-232 jack 220. The back plate 210 
and back stops 400 are provided as described above. The DB-9 key(s) 5000 
define a male connector end 520 and a female connector end 540 for 
connection to, respectively, the female connector 440 and another key 5000 
or other computer peripheral. 
FIG. 11 depicts a fourth aspect of the present invention particularly 
suitable as an external authentication key assembly for portable computers 
and for Apple computers, although it will be recognized by those skilled 
in the art that the assembly also can be mounted internally. A plastic 
case 600 encloses a housing 28, such as the housings in FIGS. 1 or 7A, 
mounted to circuit board 620 having a 9-pin end connector 640 and a 25-pin 
end connector 660. An RS-232 jack, or a SCSI port 680 is provided as an 
interface between LPT, RS-232, or SCSI cables. A locking plate cover 780 
is also provided at the end of the encased assembly to enable secure 
external use. The encased assembly may be attached to a portable computer 
by a strip of Velcro or the like (not shown), or it may be secured in 
support blocks 800. 
It will be recognized by those skilled in the art that other standard bus 
interface connectors may be used on the circuit boards used to mount the 
authentication keys shown above. For instance, other interface connectors 
such as EISA (extended industry standard architecture 32-bit), Micro 
Channel 32-bit, ISA, SC, NeXt, or Apple NuBus connectors may be on the 
selected circuit board. Additionally, the circuit board may be single or 
double sided and may have card edge connectors, a pin connector (for 
example, 8 or 16 pins) or a mating male connector at the rear most short 
side of the board. 
While this invention has been described in connection with preferred 
embodiments thereof, given the teachings herein, modifications and changes 
may be made by those skilled in the art to which it pertains without 
departing from the spirit and scope of the invention. For instance, the 
compression springs shown are an example only and any type of device 
applying appropriate pressure may be used to bias the authentication keys. 
Accordingly, the aspects discussed herein are for illustration only and 
should not limit the scope of the invention herein which is defined by the 
claims.