Cryptographic security for protecting wireless detonators

Abstract

The invention relates to a method for initiating a wireless detonation using cryptography to provide greater security in the detonation process, so that only one cryptographic device has the detonation instruction required to execute the detonation, but it can only be accessed using a cryptographic key.

Description

CRYPTOGRAPHIC SECURITY TO PROTECT WIRELESS DENOMINATORS FIELD OF INVENTION

[0001] The present invention relates to the mining and construction industries. In particular, the present invention relates to methods and systems for improving security in access to and transfer of information during wireless detonation. STATE OF THE ART

[0002] Currently, one of the problems when working with wireless initiation products, such as wireless detonators, is how to ensure that the product is safe until detonation is authorized.

[0003] To ensure the safety of the electronic detonator, the detonator can operate in an intrinsically safe mode, whereby the communication and / or power supply voltage, and indirectly the energy in the detonator, is too low to trigger initiation, or the command to charge the firing capacitor in the dual capacitor must be guaranteed. In multi-voltage wired electronic detonator systems, this is primarily achieved by limiting the output voltage to a safe level at the test and programming equipment. Blasting equipment is the only component designed to raise the voltage to a level at which the product can be detonated. In dual and multiple capacitor systems, the commands to charge the firing capacitor and to enable the detonator's firing circuit are restricted to the blasting equipment.

[0004] Both methods have proven to be safe over the many years of use of electronic detonators.

[0005] The problem becomes more problematic when wireless radio links are introduced to control the equipment or when a detonator using wireless communication is deployed.

[0006] Among the known documents is WO2021222947A1, which describes a wireless detonator assembly comprising a receiver, a memory unit, a power supply, control logic, a detonator, and explosive material. The detonator is initiated upon receiving an arming command, specifically when the receiver receives a firing command. The memory unit includes a printed circuit board with a stored key, which is hardwired during receiver manufacturing. The control logic allows the detonator to be initiated upon receiving the firing command if a received reference key, extracted from the arming command, matches the stored key. The arming command can be sent by a control device to the receiver. If the received reference key matches the stored key, the control logic, using power from the supply, generates an ignition voltage.As is known in the art, the firing voltage can be used to charge a capacitor which, after the firing command is executed, discharges under the control logic to initiate the detonator. This publication uses a printed circuit board with a stored key that is hardwired into the board during the manufacture of the detonator assembly and control logic that allows the detonator to fire only if the control logic extracts a reference key from a signal received by the receiver that is identical to the stored key. This technology focuses on securing a group or batch of products using a key that is affixed to each batch of products, but it does not actually ensure that the device is secure against explosions of the same product that would otherwise be part of another explosion.

[0007] Among the known publications is W02012061850A1, which describes a wireless blasting module that includes a receiver that, in response to at least one magnetic control signal transmitted wirelessly from a control device, produces at least one output signal, at least one first and second processors that process the at least one output signal, a power source, terminals to which a detonator component can be connected, and a switching arrangement that operates in response to a predetermined processing ratio between the first and second processors to connect the power source to the terminals.

[0008] There is also publication WO2015039147A2, which describes a method of communication with a detonator assembly in which an encryption key associated with the detonator assembly is stored in the detonator assembly and a message, intended for the detonator assembly, is encrypted at the control station using the encryption key, after which the encrypted message is transmitted to each of a plurality of detonator assemblies and each received message is decrypted and validated. Again, this technology focuses on securing a group or batch of products by means of a key that is fixed to each batch of products, but it does not actually ensure that the device is secured against explosions of the same product that would be part of another explosion.

[0009] The challenge with wireless blasting systems is ensuring the safety of the device, receiver module, and power supply connected to the detonator. Since this device most likely uses software or firmware, the challenge is always to demonstrate the security of that software. In many situations, the devices used to program or configure a detonation have entirely different software that is unaware of the detonation instructions of the electronic detonators to which it is connected. This setup has the disadvantage of requiring separate physical equipment for blasting and programming operations.

[0010] In wireless detonator systems, electronic detonators are always connected to a receiver or transceiver. In the worst-case scenario, these receivers have the blasting instruction embedded in their firmware. Therefore, if the firmware software malfunctions, the blasting sequence could be executed and transmitted to the detonator, potentially causing an unintended blast.

[0011] One alternative is to send the firing command only to the receiver just before it is used, or to transmit the firing command through the receiver directly to the detonators. The latter is problematic if the communication channel is slow compared to the typical submillisecond time interval requirements for electronic detonator systems, as it does not allow for redundancy in the electronic communication protocol.

[0012] Furthermore, redundancy in communication for the detonation sequence in a situation where a plurality of receivers are used is critical in a detonation environment due to the dangers of dealing with detonation failures in a partially fired detonation, and redundancy measures cannot be adequately implemented when the communication time is long or at least comparable to a submillisecond time, as this could disrupt the detonation sequence.

[0013] Therefore, it is desirable to improve the safety of these types of wireless deployments. A method for improving the safety of these types of wirelessly controlled equipment for wired detonator systems, and more specifically for wireless initiating devices, is described in current manuals. SUMMARY DESCRIPTION OF THE INVENTION

[0014] This invention applies to both wirelessly controlled wired detonators and fully wireless detonators. The description will focus on wireless initiation devices; however, the transmission of information from the transmitter unit to the receivers could be wired.

[0015] One alternative described here is to store the detonation sequence in an encrypted format on a cryptographic device. This way, only the cryptographic device possesses the detonation instruction necessary to execute the detonation, improving system security since no one—whether using the processing unit, the transmission unit, the receivers, or the detonators—stores the detonation instruction. With the detonation instruction protected by cryptography, even if someone gains access to the detonation cryptographic key, this is not enough to trigger the detonation; it must be decrypted by the cryptographic device. This also shortens the information transmission time to the detonators, as the encryption and decryption process can be performed at a different time than the detonation itself, for example, during the arming stage of the explosive before detonation. DESCRIPTION OF THE FIGURES

[0016] Figure 1 shows a schematic representation of a method for initiating a detonation using the present technology.

[0017] Figure 2 shows a schematic representation of a method for initiating a detonation using the present technology, where confirmation is also used through authorization codes.

[0018] Figure 3 shows a schematic representation of a method for initiating a detonation using this technology, where a second cryptographic verification process is also performed on receiving units.

[0019] Figure 4 shows a schematic representation of a methodology for triggering detonators according to the present technology.

[0020] Figure 5 shows a schematic representation of a methodology for performing a confirmation that determines whether the detonators are awake and in communication with the transmission unit. DETAILED DESCRIPTION OF THE INVENTION

[0021] In one aspect of the present application, the technology relates to a method for initiating a wireless detonation comprising: transmitting a detonation cryptographic key 101 from a processing unit 200 to a transmission unit 201; transmitting the detonation cryptographic key 101 from the transmission unit 201 to a cryptographic device 300; processing the detonation cryptographic key 101 in the cryptographic device 300 to obtain a detonation instruction 102; transmitting a detonation instruction 102 from the cryptographic device 300 to the transmission unit 201; and transmitting the detonation instruction 102 from the transmission unit 201 to one or more receivers 401 operatively connected to detonators 402.

[0022] A cryptographic key is a set or string of data that, on its own, is meaningless and uninterpretable, but is used in cryptographic algorithms to lock or unlock cryptographic functions, such as encryption, decryption, and authorization of information or data. In this case, the cryptographic algorithm is located in cryptographic device 300.

[0023] In current technology, some examples of cryptographic keys include, but are not limited to, a detonation identification number, a detonator identification number, a product identification number, a detonation hole identification or location number, a delay time, or a combination thereof. Additionally, a cryptographic key may be stored in non-transient memory of the detonators or a receiving device and used to decrypt the detonation instruction.

[0024] In this way, only cryptographic device 300 possesses the detonation instruction 102 necessary to execute the detonation, but in a form accessible only through the detonation cryptographic key 101. This enhances system security because none of the users employing processing unit 200, transmission unit 201, cryptographic device 300, receivers 401, or detonators 402 store detonation instruction 102 in a form that could be used for a detonation on its own. Since detonation instruction 102 is protected by cryptography, even if someone gains access to the detonation cryptographic key 101, this is not enough to trigger the detonation; it must be decrypted by cryptographic device 300.

[0025] The detonation instruction 102 typically corresponds to the command that each 402 detonator needs to receive to initiate the internal countdown process for igniting the detonator at time zero. The detonation instruction 102 can refer to either the full firing command or a partial firing command that allows the detonators to be armed, tested, and verified before the final detonation.

[0026] In other versions of the technology, before transmitting the detonation cryptographic key 101 from the transmission unit 201, the method also involves physically activating the cryptographic device 300. In this way, the cryptographic device 300 remains inactive until a user or group of authorized users proceeds to physically activate it, either by inserting physical security keys, energizing the cryptographic device 300, activating it using security keys, or a combination of these, adding an additional layer of protection to the system.

[0027] In other embodiments of the technology, processing the detonation cryptographic key 101 further involves processing the detonation cryptographic key 101 in the cryptographic device 300 to obtain detonation data 102b from a non-transient memory 301, and then processing the detonation data 102b in the cryptographic device 300 using the detonation cryptographic key 101 for decryption, yielding detonation instruction 102. Thus, the code for detonation instruction 102 is derived from the decrypted code, so it can only be accessed by successful decryption using the detonation cryptographic key 101. If the detonation data 102b were to be decrypted with a different key or decryption code, the decryption would yield a code that does not correspond to the detonation instruction 102 required to initiate the detonation, adding an extra layer of safety to the technology.

[0028] In other versions of the technology, processing the detonation cryptographic key 101 further involves: processing the detonation cryptographic key 101 in the cryptographic device 300 to obtain a detonation key 101b; comparing the detonation key 101b with an authorization code 103 stored in a non-transient memory 301 of the cryptographic device 300, for example, in an internal non-transient memory; and accessing the detonation data 102b in the cryptographic device 300 only when the detonation key 101b matches the authorization code 103. Thus, if a user possesses the detonation cryptographic key 101, they not only require the codes to decrypt that key, but also the appropriate authorization codes to verify the information before the detonation instruction 102 is delivered, adding an additional layer of security to the technology.

[0029] Authorization codes 103 typically correspond to a unique product key for a particular system, for example, for products based on very low frequency continuous wave (VLF CW) wireless technology. This key can also be used to uniquely identify regions or even individual customers, allowing a product to be restricted to a specific customer or region if necessary.

[0030] The cryptography process is carried out, for example, by applying Hash functions that generate a deterministic result of fixed length or a combination of functions that generate a deterministic result of fixed length, but other functions are also suitable, for example long-length cyclic redundancy checks (CRC).

[0031] In other versions of the technology, processing detonation data 102b in cryptographic device 300 using detonation cryptographic key 101 yields an encrypted detonation instruction 102a. This also involves decrypting the encrypted detonation instruction 102a in one or more receivers 401 to obtain detonation instruction 102. Each detonator or subset of detonators can be configured to activate with a different detonation instruction, which may be associated with a batch of detonators or a detonation area. When an encrypted detonation instruction 102a is used, the detonators must decrypt the instruction before activation, and therefore must have an additional cryptographic algorithm, which may differ from the one used by the cryptographic device.As mentioned earlier, a cryptographic key can be stored in a non-transient memory of the detonators or a receiving device and used when decrypting the detonation instruction.

[0032] In other versions of the technology, before detonation, a delay time associated with each detonator (402) is transmitted based on a detonator identifier (403). This allows the timing and sequence of the detonation to be programmed beforehand, reducing the time required to interpret and execute the detonation compared to when this information is contained in the same message that initiates the detonation. The delay time corresponds to the time the detonator needs to wait to ignite the fuse head after receiving the detonation instruction (102).

[0033] In other embodiments of the technology, before transmitting the detonation instruction 102 from the transmission unit 201, the method further comprises the steps of: transmitting a wake-up cryptographic key 105 from the processing unit 200 to the transmission unit 201; transmitting the wake-up cryptographic key 105 from the transmission unit 201 to the cryptographic device 300; processing the wake-up cryptographic key 105 in the cryptographic device 300 to obtain a wake-up instruction 106; transmitting a wake-up instruction 106 from the cryptographic device 300 to the transmission unit 201; transmitting the wake-up instruction 106 from the transmission unit 201 to the one or more receivers 401; and activating the receivers 401 to an activated configuration to receive detonation instructions.

[0034] In this way, detonators in a dormant configuration can be used, which on the one hand reduces the energy consumption of the detonators, minimizing firing failures due to insufficient energy in the detonator, and on the other hand, they are deactivated detonators in their dormant mode that can only be switched to their awake mode by means of a protected command within the cryptographic device 300, which can only be accessed by means of the cryptographic wake-up key 105, improving the security of the technology.

[0035] In other versions of the technology, it also involves transmitting a confirmation 107, confirming that detonator 402 is awake, from each receiver 401 to the transmission unit 201, and including a detonator identifier 403 associated with detonator 402 connected to the receiver 401 that sends the confirmation 107. The confirmation 107s are transmitted to the processing unit, which records the list of received confirmation 107s. This allows for pre-detonation verification to confirm that all detonators have received the communications and are ready to detonate.

[0036] Additionally, if any detonator fails to send its 107 confirmation, it's possible to quickly identify which detonators have not confirmed. This lack of confirmation could be due, for example, to the detonator not receiving instructions or to the confirmation not reaching transmission unit 201. In either case, knowing about this communication failure or discontinuity allows the user to make decisions such as requesting a new 107 confirmation from the detonators, or deactivating the detonators and returning them to sleep mode to check and correct the detected communication problem, thus avoiding the dangers associated with a detonator failing to fire and resulting in a misfire.

[0037] In other modalities, the technology also includes synchronizing an internal clock 404 of each detonator 402 with a master clock 204 of the transmission unit 201, so that all detonators are coordinated with the same time to perform the programmed sequential detonation.

[0038] The processing unit 200 can be, for example, a computer or a programmable board; its main function is to be the interface for inputting instructions to the system.

[0039] In another embodiment, the present technology relates to a system for initiating a wireless detonation comprising: a processing unit (200); a transmission unit 201 operatively connected to the processing unit 200 to receive a cryptographic detonation key 101; a cryptographic device 300 operatively connected to the transmission unit 201 that receives the cryptographic detonation key 101 from the transmission unit 201, processes the cryptographic detonation key 101 to obtain a detonation instruction 102, and transmits the detonation instruction 102 from the cryptographic device 300 to the transmission unit 201; one or more receivers 401 operatively connected to detonators 402, wherein the one or more receivers 401 are operatively connected to the transmission unit 201 to receive the detonation instruction 102 from the transmission unit 201.

[0040] In other modes, the cryptographic device 300 is physically activated by inserting physical security keys, powering up the cryptographic device 300, or a combination of these.

[0041] In other modalities, the cryptographic device 300 also comprises a non-transient memory 301 that stores, among other things, detonation keys 101b, detonation data 102b, authorization codes 103 and wake-up instructions 106.

[0042] In other embodiments, the transmission unit 201 comprises a master clock and each detonator 402 comprises a detonator identifier 403 and an internal clock 404.

[0043] The detonation key 101 and the wake-up key 105 can be either symmetric or asymmetric cryptographic keys. Asymmetric cryptographic keys differ from symmetric cryptographic keys in that asymmetric key algorithms use different keys for encryption and decryption, while a symmetric key algorithm uses a single key for both processes. Because multiple keys are used with an asymmetric algorithm, the process takes longer than with a symmetric key algorithm. However, the advantage lies in the fact that an asymmetric algorithm is much more secure than a symmetric key algorithm.

[0044] Using an asymmetric key involves a more complex algorithm and requires more processing time; however, it provides greater security. This is because the key must be transmitted between different devices, where there is always the possibility that it could be intercepted or manipulated during transmission. With an asymmetric key, the message and / or accompanying data can be sent or received using a public key; however, the sender or receiver would use a different private key to access the message and / or accompanying data. Therefore, asymmetric keys are suitable for transmitting confidential messages and data, and when authentication is required to ensure that the message has not been tampered with.The use of an asymmetric cryptographic key allows sending a public cryptographic key back and forth between recipients and using a different private cryptographic key that remains fixed in one location and is not transmitted back and forth, thus keeping it safe from being intercepted during transmission.

[0045] In some versions of this technology, a receiver cryptographic key is stored in a non-transient memory of the receivers 401 or in a non-transient memory of the detonators 402. The stored receiver cryptographic key may be the detonation cryptographic key 101 or it may be a different cryptographic key, such as a private cryptographic key different from the detonation cryptographic key 101. The receiver cryptographic key is used to decode received messages and / or accompanying data.

[0046] Cryptographic keys such as detonation cryptographic key 101, awakening cryptographic key 105, or receiver cryptographic key may include, but are not limited to, a detonation identification number, a detonator identification number, a product identification number, a detonation borehole identification or location number, a delay time, or a combination thereof.

[0047] Figure 1 shows a schematic representation of a method for initiating a detonation using the present technology where a cryptographic detonation key 101 is transmitted to the cryptographic device 300 to obtain a detonation instruction 102 which is then transmitted to receivers 401 and their respective detonators 402.

[0048] Figure 2 shows a schematic representation of a method for initiating a detonation using the present technology, which also employs confirmation via authorization codes. The detonation cryptographic key 101 is processed in the cryptographic device 300 to obtain a detonation key 101b, which is compared with authorization codes stored in a non-transient memory 301 to obtain detonation data 102b from the non-transient memory 301. This detonation data 102b is then processed in the cryptographic device 300 using the detonation cryptographic key 101, resulting in detonation instruction 102. Schematic representations of the detonator's internal clocks 404 and the master clock 204 are also illustrated in this figure.

[0049] Figure 3 shows a schematic representation of a method for initiating a detonation using this technology, which also includes a second cryptographic verification process on receiving units. Receivers 401 receive an encrypted Detonation Instruction 102a, which is then decrypted to obtain a Detonation Instruction 102. This instruction is used to activate detonators 402. Preferably, this is a two-part activation process. The decryption of the encrypted Detonation Instruction 102a is not performed simultaneously with the final detonation to prevent any delays in the decryption process from affecting the detonation timing of each detonator.

[0050] Figure 4 shows a schematic representation of a methodology for waking detonators according to the present technology where the process of activating the detonators is protected by the cryptographic device and requires a cryptographic wake-up key 105 to obtain the wake-up instruction 106.

[0051] Figure 5 shows a schematic representation of a methodology for performing a confirmation that determines whether the detonators are awake and in communication with the transmission unit. Each detonator 402 communicates its detonator identifier 403 in a communication 107 that is received by the transmission unit 201 and transmitted to the processing unit 200. In the lower right of the figure, a receiver 401 and a detonator 402 that do not send confirmation communication 107 are schematically represented. REFERENCE NUMBERS

[0052] A list of the components of the invention and their respective reference numbers is included below in the figures. 101 Cryptographic detonation key 101b Detonation Key 102 Detonation Instruction 102a Encrypted detonation instruction 102b detonation data 103 Authorization Code 105 Cryptographic key to wake up 106 Wake-up Instruction 107 Confirmation 200 Processing Unit 201 Transmission unit 204 Master Clock 300 Cryptographic device 301 Non-transitory memory 401 Receiver 402 Detonator 403 Detonator Identifier 404 Internal Clock

[0053] Finally, it should be noted that various specific parameters of the invention, such as dimensions, choice of materials, and specific aspects of the preferred configurations described above, may vary or be modified according to operational requirements. Consequently, the specific configurations described above are not intended to be limiting, and such variations and / or modifications are within the spirit and scope of the invention.

Claims

CLAIMS 1. A method for initiating a wireless detonation comprising the steps of: transmit a cryptographic detonation key (101) from a processing unit (200) to a transmission unit (201); transmit the detonation cryptographic key (101) from the transmission unit (201) to a cryptographic device (300); process the detonation cryptographic key (101) on the cryptographic device (300) to obtain a detonation instruction (102); transmit a detonation instruction (102) from the cryptographic device (300) to the transmission unit (201); transmit the detonation instruction (102) from the transmission unit (201) to one or more receivers (401) operatively connected to detonators (402).

2. The method of claim 1 wherein, prior to transmitting the cryptographic detonation key (101) from the transmission unit (201), the method further comprises physically activating the cryptographic device (300).

3. The method of claim 1, wherein the cryptographic detonation key (101) includes one of a detonation identification number, a detonator identification number, a product identification number, a detonation borehole identification or location number, a delay time, or a combination thereof.

4. The method of claim 1 wherein the cryptographic detonation key (101) is further stored in a non-transient memory of the receivers (401) or in a non-transient memory of the detonators (402).

5. The method of claim 1 wherein processing the cryptographic detonation key (101) further comprises process the detonation cryptographic key (101) in the cryptographic device (300) to obtain detonation data (102b) from a non-transient memory (301); and process the detonation data (102b) in the cryptographic device (300) using the detonation cryptographic key (101) to obtain the detonation instruction (102).

6. The method of claim 4 wherein processing the cryptographic detonation key (101) further comprises: decrypting the cryptographic detonation key (101) in the cryptographic device (300) to obtain a detonation key (101b); compare the detonation key (101b) with an authorization code (103) stored in a non-transient memory (301) the cryptographic device (300); access the detonation data (102b) in the non-transient memory (301) only when the detonation key (101b) matches the authorization code (103).

7. The method of claim 1 wherein the detonation instruction (102) delivered by the cryptographic device (300) is an encrypted detonation instruction (102a) and the method further comprises the step of decrypting the encrypted detonation instruction (102a) in the one or more receivers (401).

8. The method of claim 1 wherein it further comprises the step of transmitting a delay time associated with each detonator (402) based on a detonator identifier (403).

9. The method of claim 1 wherein prior to transmitting the detonation instruction (102) from the transmission unit (201) the method further comprises the steps of: transmitting a cryptographic wake-up key (105) from the processing unit (200) to the transmission unit (201); transmit the wake-up cryptographic key (105) from the transmission unit (201) to the cryptographic device (300); process the wake-up cryptographic key (105) on the cryptographic device (300) to obtain a wake-up instruction (106); transmit a wake-up instruction (106) from the cryptographic device (300) to the transmission unit (201); transmit the wake-up instruction (106) from the transmitting unit (201) to the one or more receivers (401); activate the receivers (401) to an activated configuration to receive detonation instructions.

10. The method of claim 9 further comprising transmitting a confirmation (107) confirming that the detonator (402) is awake from each receiver (401) to the transmission unit (201) and including a detonator identifier (403) associated with the detonator (402) connected to the receiver (401) that sends the confirmation (107).

11. The method of claim 1 further comprising synchronizing an internal clock (404) of each detonator (402) with a master clock (204) of the transmission unit (201).

12. A system for initiating a wireless detonation comprising: a processing unit (200); a transmission unit (201) operatively connected to the processing unit (200) to receive cryptographic detonation key (101); a cryptographic device (300) operatively connected to the transmission unit (201) that receives the detonation cryptographic key (101) from the transmission unit (201), processes the detonation cryptographic key (101) to obtain a detonation instruction (102) and transmits the detonation instruction (102) from the cryptographic device (300) to the transmission unit (201); one or more receivers (401) operatively connected to detonators (402), wherein the one or more receivers (401) are operatively connected to the transmission unit (201) to receive the detonation instruction (102) from the transmission unit (201).

13. The system of claim 12 wherein the cryptographic device (300) is physically activated by inserting physical security keys, energizing the cryptographic device (300), or a combination thereof.

14. The system of claim 12 wherein the cryptographic device (300) further comprises a non-transient memory (301).

15. The system of claim 12 wherein the transmission unit (201) comprises a master clock and each detonator (402) comprises a detonator identifier (403) and an internal clock (404).

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