[0001] Referring to the present descriptive report of the Utility Model of a security keyboard,
as the opportunity for its designation, in order to protect information and secret
processes stored by electronic means against unauthorized access.
[0002] The point of sale terminals (POS, PDV, Pinpad, encrypted keyboard) allow the clients
to pay their bills using several payment methods, such as credit cards, debit cards,
smart cards and others.
[0003] To guarantee that the payment information is not intercepted from one of the sales
point terminals until the center of payments, such information is normally encrypted
and protected during transmission, using, for example, digital authentication technology.
Therefore, the confidential payment information, keyed in by the user at a Point of
Sale, could be intercepted by a physical violation of the Point of Sale
[0004] To impede any violation and consequent digital information interception, the keyboard
in question, the object of this report, is assembled in a way as to guarantee the
inviolability of its internal content, setting off an intruder alarm at any attempt
at front, rear or side manipulation or mechanical perforation of any internal part
of the keyboard or of the circuits activated by its keys.
[0005] The referred intrusion alarm sets off a security mechanism, which destroys stored
information, going back to the security concept of the former cryptex.
[0006] The major part of the solutions found currently do not have a security mechanism
for the detection of intrusion circuits inserted in the keyboard, based on circuits
mounted externally to the printed circuit board where the keyboard buttons to be operated,
close the exposed terminals.
[0007] The standard activating mechanism of a keyboard system consists of a rigid printed
circuit board containing a demarcated area, two open exposed terminals, connected
to an electronic circuit which, for its turn, detects the closing of these contacts.
Each keyboard is connected to a conducting element in the face around the contacts,
in such a way, when pressing the key, the conducting element touches the two contacts
closing them in a circuit, allowing the keyboard processor to decode any key operated.
[0008] An observed disadvantage in the conventional solutions is that they allow the occurrence
of frauds by the means of the introduction of a device between the circuit board and
the keyboard button, detecting the keys and the pressing sequence of them, allowing
the capture of personal identity numbers (PIN) and other secret information of the
user.
[0009] One of the objectives of this Utility Model is to provide a constructive device for
a keyboard in order to impede the insertion of unauthorized access devices into their
internal circuits, guaranteeing the internal inviolability of installed equipment
at the point of sale and providing a significant increase in security of the keyboard
system.
[0010] Therefore, in order to allow a better clarification of the object in question, let's
proceed to its detailed description with reference to the drawings below where:
Figure 1 illustrates in exploded perspective view the keyboard circuit layers;
figure 2 illustrates a front view of the upper face of the malleable security circuit;
figure 3 illustrates a front view of the lower face of the malleable security circuit;
figure 4 illustrates a front view of the lower face above the malleable contacts circuit;
figure 5 illustrates a front view of the upper face of the malleable contacts circuit;
figure 6 illustrates a front view of the lower face of the spacer.
[0011] In conformity with the illustrated figures mentioned above, the security keyboard,
objective of this Utility Model, is made up of a rigid printed circuit (1), having
an insulating flexible membrane (2), of a determined thickness, with holes (3) located
over the position of the two exposed contacts (4), with the function of a spacer over
which the malleable electronic circuit is placed (5) with some conductive material,
in the lower face, aligned with the exposed contacts (4) of the rigid printed circuit
(1), being the keyboard (8) separated from the rest of the assembly by a malleable
electronic protection board (6), which indicates any break in its circuit.
[0012] Due to the presence of the flexible membrane (2) between the malleable electronic
circuit (5) and the rigid printed circuit (1), the conducting material does not close
the contacts, in spite of the hole present in that position. The mechanical key, in
this case, does not have the capability of closing the contact, but presses the conducting
material of the malleable electronic circuit on the membrane spacer, deforming it
until the conducting material enters into contact with the two exposed contacts(4)
and closes the circuit, signaling to the processor element that the contact was closed.
[0013] The first mechanism additional to the traditional system refers to the insertion
of a malleable electronic protection circuit (6), between the keyboard (8) and the
malleable electronic circuit of the contacts (5), as illustrated in figure 1, in a
way so as to create a physical barrier against mechanical attacks of the perforating,
obliteration, cutting or short circuiting chemicals types.
[0014] The said malleable electronic protection circuit (6) has on both faces, multiple
electronic circuits in a coil form, with a random design, running through the circuit
surface in a dense physical mesh. On each face of the malleable circuit, there are
two independent circuits, positioned near each other, whose terminals are linked in
a security circuit which when detecting any anomaly sets off a security alarm which
will generate the protection and security procedures of the Point of Sale terminal.
[0015] From each of these circuits is transmitted a digital electronic signal in a waveform
and univocal frequency, generated by the security circuit which is monitored by the
security circuit receiver. In other words, each circuit has a signature permanently
monitored by the security circuit.
[0016] If there is a perforating type violation attempt which breaks any segment of this
circuit, it is immediately detected by the security circuit.
[0017] If there is a chemical violation attempt by short circuiting the mesh, seeking to
make it possible to subsequently break the protection circuit, the alarm will be set
off, because there are two circuits with different signatures and the security circuit
is not capable of distinguishing the signatures of each circuit in the case of a short
circuit in the mesh.
[0018] The protection circuits have very complex random designs, in order to make it difficult
for a violator to check the circuit visually and find its respective terminals.
[0019] The malleable protection circuit has a larger size than the keyboard activating circuits,
seeking to completely cover physically the lower keyboard circuits, in a way to impede
side attacks to the keyboard system.
[0020] To impede the attempt at separating the many keyboard system components, usually
seeking to insert electronic devices, independent monitoring circuits are positioned,
starting at the lower rigid printed circuit and connecting to the upper invasion monitoring
circuit, at the ends of this circuit, returning to the lower rigid circuit, in a position
diametrically opposite the input.
[0021] Again, each circuit has a digital signature with its own frequency and waveform,
impeding a crossover short circuit. The mechanical contact between the upper and lower
circuits occurs through projections in the keyboard or the lid of the device, which
exert enough mechanical pressure to maintain the circuits closed. In an attempt to
separate the diverse elements in the keyboard system, these contacts are opened, activating
security sensors in the point of sale terminal.
[0022] Preferably, the separation detection circuits between the keyboard system components
can be provided with an intermediate conductor circuit, which stays closed by mechanical
pressure between the mechanical keyboard and the device lid. If an invasion occurs
in this secure area, the sensor activating communicates to the processor which then
destroys all the secret information stored in the electronic memory.
[0023] Without this information, it is impossible to recuperate the secret information stored
in the memory as well as carry out secret processes turning the equipment inoperable.
[0024] Regarding the signatures generated by each monitoring mesh circuit, inside the microprocessor
there is a true random number generator. The random numbers of this generator are
used to create signal forms of amplitude, frequency and phase parameters for the sensor.
These signals pass through the sensor group and return to the microprocessor, whose
comparing circuits check the referred parameters of the original signals.
[0025] Detecting differences in the parameters, the invasion alarm circuit is activated
and immediately secret information is destroyed turning the equipment inoperable and
making it impossible to recuperate the information.
[0026] The constructive disposition presented here is not limited to any specific format
or to its constructive sequence, presuming there are numerous variations in the present
constructive of a security keyboard for information and secret processes stored by
electronic means without impairing the objective of this Utility Model.
1. "CONSTRUCTIVE DEVICE INTRODUCED INTO A SECURITY KEYBOARD FOR INFORMATION AND SECRET
PROCESSES STORED BY ELECTRONIC MEANS" characterized by a rigid printed circuit (1), having an insulating flexible membrane (2), of a determined
thickness, with holes (3) located over the position of the two exposed contacts (4),
with the function of a spacer over which the malleable electronic circuit is placed
(5) with some conductive material, in the lower face, aligned with the exposed contacts
(4) of the rigid printed circuit (1), being the keyboard (8) separated from the rest
of the assembly by a malleable electronic protection board (6), which indicates any
break in its circuit.
2. "CONSTRUCTIVE DEVICE INTRODUCED INTO A SECURITY KEYBOARD FOR INFORMATION AND SECRET
PROCESSES STORED BY ELECTRONIC MEANS", in agreement with Claim 1, characterized by including a protective mechanism for a keyboard system which makes attacks impossible
by mechanical manipulation, mechanical perforation, part separation, chemical short
circuits or the insertion of intrusive devices.
3. "CONSTRUCTIVE DEVICE INTRODUCED INTO A SECURITY KEYBOARD FOR INFORMATION AND SECRET
PROCESSES STORED BY ELECTRONIC MEANS", in agreement with Claim 1, characterized by the insertion of a malleable electronic protective circuit (6), between the keyboard
and malleable electronic circuit with contacts (5) in a way as to create a physical
barrier against attacks of the perforating mechanical type, obliteration, cutting
or chemical short circuits
4. "CONSTRUCTIVE DEVICE INTRODUCED INTO A SECURITY KEYBOARD FOR INFORMATION AND SECRET
PROCESSES STORED BY ELECTRONIC MEANS", in agreement with Claim 3, characterized by the input and output of monitoring points of a same circuit to be positioned diametrically
opposite, in a cross form or passed between the circuits, making it impossible to
insert intrusive devices in various angles of attack.
5. "CONSTRUCTIVE DEVICE INTRODUCED INTO A SECURITY KEYBOARD FOR INFORMATION AND SECRET
PROCESSES STORED BY ELECTRONIC MEANS", in agreement with Claim 3 characterized by the fact said malleable electronic protection circuit (6) has on both faces, a double
electronic circuit in a coil form, with a complex random design, running through the
circuit surface in a dense physical mesh, there are each face of the malleable circuit,
two independent circuits, positioned near each other, whose terminals are linked in
a security circuit which when detecting any anomaly sets off a security alarm responsible
for generating the protection and security procedures of the Point of Sale terminal.
6. "CONSTRUCTIVE DEVICE INTRODUCED INTO A SECURITY KEYBOARD FOR INFORMATION AND SECRET
PROCESSES STORED BY ELECTRONIC MEANS", in agreement with Claim 1, characterized by the use of a multiple monitoring circuit with a complex random design pattern which
makes it difficult to follow the circuit logic, making it impossible to visually identify
the input and output terminals of each circuit by possible fraudsters.
7. "CONSTRUCTIVE DEVICE INTRODUCED INTO A SECURITY KEYBOARD FOR INFORMATION AND SECRET
PROCESSES STORED BY ELECTRONIC MEANS", in agreement with Claim 1, characterized by the use of a monitoring circuit of larger dimensions than the lower circuits, forming
a protective area, impeding side attacks on the keyboard system.
8. ""CONSTRUCTIVE DEVICE INTRODUCED INTO A SECURITY KEYBOARD FOR INFORMATION AND SECRET
PROCESSES STORED BY ELECTRONIC MEANS", in agreement with Claim 1, characterized by the use of a printed circuit below the keyboard, which has an internal layer with
electric circuits in a coil form, responsible for the detection of invasion or attack
attempts on the lower part of the keyboard.
9. ""CONSTRUCTIVE DEVICE INTRODUCED INTO A SECURITY KEYBOARD FOR INFORMATION AND SECRET
PROCESSES STORED BY ELECTRONIC MEANS", characterized by the insertion of a flexible security circuit consisting of diverse traces that delineate
circuits whose contacts are maintained closed by projections located in the terminal
cabinet of the point of sale and in the mechanical keyboard, in a way so that any
attempt to separate mechanically any component of the keyboard system causes these
circuits to open, setting off a security system.
10. "CONSTRUCTIVE DEVICE INTRODUCED INTO A SECURITY KEYBOARD FOR INFORMATION AND SECRET
PROCESSES STORED BY ELECTRONIC MEANS", in agreement with Claim 9, characterized by the fact that the said monitoring traces are proof against chemical or mechanical
attack that causes a short circuit in the monitoring mesh.
11. "CONSTRUCTIVE DEVICE INTRODUCED INTO A SECURITY KEYBOARD FOR INFORMATION AND SECRET
PROCESSES STORED BY ELECTRONIC MEANS", in agreement with Claim 9, characterized by the fact that each circuit has a digital signature with its own frequency and waveform,
impeding a crossover short circuit.