WO2018091053A1

WO2018091053A1 - Electronic cable seal

Info

Publication number: WO2018091053A1
Application number: PCT/DK2017/050376
Authority: WO
Inventors: Oleg Iagounov
Original assignee: Lyngsoe Systems Ltd
Priority date: 2016-11-15
Filing date: 2017-11-15
Publication date: 2018-05-24

Abstract

A radio frequency identification (RFID) adaptor is provided for tamper detection of a cable seal. The RFID adaptor comprises a u-shaped housing, an insert and an RFID tag. The u-shaped housing comprises a cable hole in a closed end thereof. The insert is positioned within the housing and comprises a blind channel and a through channel. The blind channel terminates within the insert. The through channel passes though the insert and is configured to be aligned with the cable hole. The RFID tag is positioned proximal the insert and comprises a pair of contacts. Each contact comprises at least one cut to allow a portion of cable of the cable seal to pass there through. Each con- tact is configured to be aligned with a corresponding one of the blind channel and the through channel.

Description

ELECTRONIC CABLE SEAL

FIELD OF THE INVENTION The present invention relates generally to cable seals for containers and specifically to an electronic cable seal adaptor that provides tamper detection. It also relates to a combination of the cable seal and the adaptor.

BACKGROUND OF THE INVENTION

In the shipping industry, container security has become an important factor. Specifically, loaded containers are locked to prevent unauthorized access from the time the container is shipped until the time the container reaches its destination. This is partic- ularly true when shipping containers travel great distances or across borders.

In order to secure the container, cable seals in accordance with standards such as ISO 17712:2013 Freight containers - Mechanical seals are used to lock the container doors. When the container is in transit an unauthorized third party may attempt to access the container by removing or otherwise tampering with the cable seal. Such attempts have become sufficiently sophisticated that it can be very difficult, if not impossible to visually determine whether or not the cable seal has been compromised. Therefore, it is important that tampering with the cable seal can be detected using other means. To assist with the identification of lock tampering, electronic seals have been designed. One form of electronic seal that has been used in the past is an electronic tagging device that wirelessly transmits information to an interrogator. This information identifies whether the lock has been tampered with.

For example, U.S. Patent No. 6,265,973 to Brammall et al. describes an electronic security seal. A conductor along the bolt shank is connected to a circuit and provides a tamper evident signal to the circuit when the bolt is severed. The circuit senses removal of the bolt or severed bolt condition and generates a "tamper" signal, which is transmitted to a local receiver/reader. As another example, U.S. Patent No. 7,239,238 to Tester at al. describes a battery operated cable security seal for cargo containers that includes a housing with a transparent cover for visual inspection of illuminated internal green or red LEDs. The red LED represent a tampered state of a stranded metal locking cable, which has a length sufficient to secure the keeper bars and hasp of a cargo container door. The LED are part of an electronic circuit board placed adjacent to the cable and connected to the cables by wires.

Brazilian patent application PI0503404-3A by Moeller, Purim, Wolaniak and Pereira discloses an electronic traceable seal with an RFID tag, where the cable extends through the seal. Brazilian patent application PI0506086-9 by da Silva, Rosatelli and Rodrigues discloses an electronic seal with an RFID tag for satellite tracking. Other electronic seals are disclosed in US2009/0299606, US2007/262850, US2006/020282, US6002343. US6069563, and US5097253.

A major disadvantage of providing sophisticated electronic security seals is the in- creased cost. Even if the devices are made to be reusable, there is the associated cost, inconvenience and possible additional security issues related to the reuse of electronic seals. Further, the mechanical portion of the seal is typically made of high gauge components and the seal is installed on large metal containers. This environment is difficult for wireless communications.

DESCRIPTION / SUMMARY OF THE INVENTION

Accordingly, it is an objective of the present invention to provide an improvement in the art. In particular, it is an objective to obviate or mitigate at least some of the above mentioned disadvantages with electronic seals, or at least to provide the public with a useful alternative. The objective is achieved with an RFID adapter as described in the following.

In accordance with an aspect of an embodiment, there is provided a radio frequency identification (RFID) adaptor for providing tamper detection of a cable seal, the RFID adaptor comprising: a u-shaped housing comprising a cable hole in a closed end thereof; an insert positioned within the housing, the insert comprising a blind channel and a through channel, wherein the blind channel terminates within the insert, the through channel passes though the insert, and the through channel is configured to be aligned with the cable hole; and an RFID tag positioned proximal the insert, the RFID tag comprising a pair of contacts, each contact comprising at least one cut to allow a portion of cable of the cable seal to pass there through, wherein each contact is con- figured to be aligned with a corresponding one of the blind channel and the through channel.

The u-shaped housing is cup-shaped, for example cylindrical, for receiving and coupling to a cable seal of the type including an electrically conducting cable and a body, the body including a pair of seal bores extending vertically there through, wherein each seal bore includes a one-way lock configured to allow a corresponding end of the cable to be inserted through the seal bore and inhibit their removal therefrom.

The term "vertically" is used for a direction laterally through the opening and the u- shaped bottom of the cup-shaped housing. The term "horizontal" is used for a direction perpendicular thereto. The opening for receiving the cable seal is typically hori- zontal within these terms. The term cup-shaped is used for a largely cylindrical shape having one open end for insertion of the cable seal.

Each contact is configured for establishing electrical connections, respectively, to a first portion of the cable in the blind channel and a second portion of the cable in the through channel. The RFID tag is configured for determining electrical conduction through the cable for determining whether the cable is intact or not and for indicating this by transmission of an RFID signal. For example, the electrical current or resistance is measured. Optionally, the RFID tag transmits an identification signal only when the cable seal is closed and the two contacts are electrically connected through the cable. For example the RF identification signal includes a tamper bit indicating whether the measured resistance falls within a predefined range. Optionally, the identification signal includes a representation of the measured resistance.

For example, the two contacts are electrically isolated from each other and connect through the cable only. Optionally, the RFID tag comprises two circuits which are electrically isolated when the cable seal is open and electrically connected when the cable seal is closed.

In some embodiments, the RFID adapter is configured for using the cable as part of a radio antenna. Optionally position and/or length of the cable controls the radio sensi- tivity and transmit power of the RFID tag.

Optionally, the RFID tag transmits an identification signal when the cable seal is closed.

In some embodiments, the RFID adaptor comprises a pressure layer positioned between the RFID tag and the insert, the pressure layer comprising a pair of cuts config- ured to be aligned with the contacts of the RFID tag. For example, the pressure layer comprises closed cell foam or rubber and potentially assists electrical connection between the contacts and the conductive wire.

In some embodiments, the RFID comprises a protective layer positioned adjacent the RFID tag on a side of the RFID tag distal from the insert. Optionally, the protective layer comprises a gel for weather protecting the contacts.

Advantageously, a circuit is configured to transmit an identification signal along with a tamper bit, the tamper bit indicating whether the cable is intact or has been compromised. For example, the RFID tag is configured detect whether the cable is intact, reset the tamper bit if the cable is intact, and set the tamper bit if the cable has been compromised. Optionally, the RFID tag further comprises a latch to store the tamper bit once it is determined that the cable has been compromised. As a further option, the RFID tag comprises a latch to store the tamper bit once the tamper bit has been set.

In some aspects, the RFID adaptor comprises a third contact position proximal the cable hole and configured to be aligned with the through channel. Optionally, it com- prises a second protective layer between the RFID tag and the u-shaped housing.

In some embodiments, the RFID tag further comprises an Application-Specific Integrated Circuit (ASIC) configured to measure the resistance of the cable. Optionally, the RFID comprises a battery configured to activate the ASIC, wherein the ASIC is only activated when the cable has been passed through all three contacts. The invention also concerns the combination of the RFID adapter and the cable seal.

SHORT DESCRIPTION OF THE DRAWINGS Embodiments of the invention will now be described by way of example only with reference to the following drawings in which:

Figure la is an block diagram of a mechanical seal;

Figure lb is a block diagram of an RFID adaptor;

Figure lc is a block diagram of an electronic seal; and

Figure 2 is a block diagram of an alternative RFID adaptor.

DETAILED DESCRIPTION / PREFERRED EMBODIMENT

For convenience, like numerals in the description refer to like structures in the draw- ings. Referring to Figure la, a mechanical seal, in the form of a cable seal, is illustrated generally by numeral 100. The cable seal 100 includes a cable 102 and a body 104. The body 104 includes a pair of seal bores 106 extending vertically there through. Each seal bore 106 includes a one-way lock 108. The one-way 108 lock is configured to allow a corresponding end of the cable 102 to be inserted through the seal bore 106 and inhibits their removal therefrom. In an embodiment, the cable 102 is a steel cable.

Referring to Figure lb, a radio frequency identification (RFID) adaptor in accordance with an embodiment of the present invention is illustrated generally by numeral 130. The RFID adaptor 130 comprises a housing 132, an insert 134, a RFID tag 136, a protective layer 138, and a pressure layer 140. The housing 132 is shaped to couple with the body 104 of the cable seal 100. Accordingly, in the present embodiment, the housing 132 is u-shaped. An open end 132a of the housing 132 is configured to receive the insert 134, the RFID tag 136, the protective layer 138, and the pressure layer 140. An opposing, closed end 132b of the housing 132 includes a cable hole 133. The cable hole 133 is position proximal one side of the housing 132. The insert 134 is shaped to fit snugly in the housing 132. The insert 134 comprises a blind channel 135a and a through channel 135b. The blind channel 135a terminates within the insert 134 and, therefore, does not extend entirely there through. In contrast, the through channel 135b extends entirely through the insert 134. As a result, a first end 134a of the insert 134 has two openings. One opening provides access to the blind channel 135a and another opening provides access to the through channel 135b. A second, opposing end 134b of the insert 134 has only one opening that provides access to the through channel 135b. The insert 134 is configured to be positioned in the housing 132 so that the second end 134b of the insert 134 is proximal to or abuts the closed end 132b of the housing 132. Further, the opening of the through channel 135b is aligned with the cable hole 133 in the housing 132. The first end 134a of the insert faces the open end 132a of the housing 132.

The pressure layer 140 is shaped to fit within a horizontal cross-section of the housing 132. The pressure layer 140 is placed adjacent the first end 134a of the insert 134 within the housing 132. The pressure layer 140 comprises a pair of cross-shaped cuts 141. The cuts 141 are configured to be aligned with the openings in the first end 134a of the insert 134. The pressure layer 140 comprises closed cell foam, rubber, or the like.

In an embodiment, the RFID tag 136 comprises a flexible Ultra High Frequency (UHF) RFID inlay. The RFID inlay 136 is configured in two electrically isolated circuits. Each circuit of the RFID 136 inlay comprises an inlay contact 137. Each inlay contact 137 is nickel plated and includes a cross-shaped cut 137a. The RFID inlay 136 is larger than the horizontal cross section of the housing 132. Accordingly, the RFID inlay 136 is folded into three portions. A first side portion of the RFID inlay 136 is positioned along a first side of the insert 134, between the insert 134 and the housing 132. A middle portion of the RFID inlay 136 is positioned adjacent the pressure layer 140. A second side portion of the RFID inlay 136 is positioned along a second, opposing side of the insert 134, between the insert 134 and the housing 132. The contacts 137 are positioned in the middle portion so that when the RFID inlay 136 is placed over the pressure layer 140 and the insert 134, the cross-shaped cuts 137a of the contacts 137 are aligned with the cross shaped cuts 141 of the pressure layer 140. The protective layer 138 is configured to fit within the horizontal cross-section of the housing 132. The protective layer 138 is placed adjacent the RFID inlay 136 within the housing 132. The protective layer 138 protects the RFID inlay 136 from external elements, such as the weather, dust, dirt, and the like. In an embodiment, the protec- tive layer comprises a gel.

In addition to the insert 134, the pressure layer 140, the RFID inlay 136, and the protective layer 138, the housing 132 is also configured to receive at least a portion of the body 104 of the cable seal 100 to couple therewith.

Referring to Figure lc, an electronic seal is illustrated generally by number 170. The electronic seal 170 comprises the body of the cable seal 100 coupled with the RFID adaptor 130. The electronic seal 170 is illustrated in a locked position. In an unlocked position, the cable 102 would be absent or only present through one of the seal bores 106.

As shown, a first end of the cable 102 has been passed through one of the seal bores 106, the protective layer 138, one of the cross-shaped cuts 137a in the contacts 137, one of the cross shaped cuts 141 in the pressure layer 140, and into the blind channel 135a of the insert 134. A second end of the cable 102 has been passed through the other of the seal bores 106, the protective layer 138, the other of the cross-shaped cuts 137a in the contacts 137, the other of the cross shaped cuts 141 in the pressure layer 140, the through channel 135b of the insert 134, the cable hole 133 and protrudes from the housing 132.

As shown in Figure lc, the cross-shaped cut 137a in the contact 137 allows the cable 102 to pass through while deforming the contact 137. Such a deformation maintains a physical connection between the contact 137 and the cable 102. Similarly, the cross- shaped cut 141 in the pressure layer 140 allows the cable 102 to pass through while deforming the pressure layer 140. Such a deformation traps the contact 137 between the cable 102 and the pressure layer 140. Thus, the pressure layer 140 helps to reinforce or maintain the physical connection between the contact 137 and the cable 102.

The cable 102 also provides an electrical connection between the electrically isolated circuits of the RFID inlay 136. Accordingly, when both ends of the cable 102 are inserted into the electronic seal 170, the RFID inlay 136 can transmit an identification signal. If the cable 102 is cut, the electrical connection between the two circuits on the RFID inlay 136 is broken and the identification signal cannot be transmitted.

In this configuration, the cable 102 is used as part of the radio antenna through one of more of magnetic coupling, capacitive coupling, or a direct electrical connection to an integrated receive and/or transmit antenna in the RFID inlay 136. Restricting or controlling the position and length of the cable 102 can control radio receive sensitivity and transmit power by changing physical characteristics of the combined antenna.

In an alternative embodiment, the RFID inlay 136 comprises a single electronic circuit. The RFID inlay 136 is further configured to set a tamper bit, which is transmit- ted along with a seal identifier as part of the identification signal. For example, the RFID inlay 136 is configured to reset a tamper bit to '0' if the cable 102 is in tact, thereby completing the circuit between the contacts 137. The tamper bit is set to Ί ' if the cable 102 has been compromised, thereby creating an open circuit between the contacts 137. In an alternative embodiment, the RFID inlay 136 further comprises a battery and a latch. The latch is configured to store the tamper bit if it is determined at any point that the cable 102 has been compromised. Therefore, if the unauthorized third party tampers with the seal 730, the tamper bit will be latched. A subsequent attempt by the third party to re-establish the integrity of the cable 102 to avoid visual detection that the cable 102 has been compromised will not affect the latched tamper bit, even if the electrical connection between the contacts 137 is re-established.

Referring to Figure 2, an RFID adaptor in accordance with an alternative embodiment of the present invention is illustrated generally by numeral 200. The RFID adaptor 200 comprises the housing 132, the insert 134, the RFID inlay 136, the protective lay- er 138, and the pressure layer 140.

In the present embodiment, the RFID inlay 136 further includes a battery 202, an Application-Specific Integrated Circuit (ASIC) 204, and is folded into four portions instead of three. The fourth portion of the RFID inlay 136 is positioned below the insert 134. The fourth portion of the RFID inlay includes a third contact 137. The third con- tact 137 is configured to be aligned with the through channel 135b of the insert 134 and the cable hole 133. A second protective layer 138 is placed over the third contact 137.

The battery 202 is inactive until the second end of the cable 102 has been passed through the other of the seal bores 106, the protective layer 138, the other of the cross- shaped cuts 137a in the contacts 137, the other of the cross shaped cuts 141 in the pressure layer 140, the through channel 135b of the insert 134, and the third contact 137. That is, the RFID inlay 136 maintains an open circuit to the battery 202 until the cable 102 has been inserted into the electronic seal 200. Once the cable 102 has been inserted, the battery 202 is considered to be active. Likewise, the electronic seal 200 is considered to be active.

In the present embodiment, the cable 102 comprises resistive wire and is coupled with the ASIC 204. The ASIC 204 measures the resistance of the cable 102 once the electronic seal 200 is active. Most, if not all, attempts to tamper with the cable 102 will result in a change of resistance. For example, the unauthorized third party may at- tempt to attach a bypass cable to the cable 102 prior to tampering with it. Such a bypass cable will maintain an electrical connection even when the cable 102 is cut, making it more difficult to detect the tampering attempt. However, use of the bypass cable will likely affect the resistance of the cable 102 and the attempt to tamper with the cable can be detected by the ASIC 204. In one example, if the resistance of the cable 102 falls outside of a predefined range, it can be determined that the cable 102 has been tampered with. Similar to a previous embodiment, the ASIC can reset the tamper bit to '0' if the resistance of the cable 102 stays within the predefined range. The ASIC can set the tamper bit to T if the resistance of the cable 102 strays outside the predefined range, suggesting that cable 102 has been compromised

In another example, the RFID inlay 136 may transmit a representation of the measured resistance along with the identification signal.

Optionally, one or more light emitting diodes (LEDs) 206 can be used to provide visual indicators of the status of the electronic seal 200. For example, the LED can be used to identify when the electronic seal 200 is active. As another example, the LED can be used to identify that the electronic seal 200 has been tampered with. In an alternative embodiment, the cable 102 comprises an insulated wire or optical cable rather than a resistive wire. The ASIC 204 is configured to transmit a coded signal through the insulated wire or optical cable. If the cable 102 is cut and the coded signal is interrupted, then a tamper event is detected.

In an alternative embodiment, the cable 102 comprises a coaxial cable. For example, an inner cable of the coaxial cable can be the resistive wire and an outer cable of the coaxial cable can be the steel cable. In another example, the inner portion of the coaxial cable can be the insulated wire and the outer portion of the coaxial cable can be the steel cable. In yet another example, the inner portion of the coaxial cable can be the optical cable and the outer portion of the coaxial cable can be the steel cable.

For example, the RFID inlay 136 may be configured to set the tamper bit to T if the cable 102 is intact and to '0' if the cable 102 has been compromised. The RFID tag 136 may comprise wet or dry inlay. The RFID tag 136 can transmits at different frequencies depending on the implementation. Different metals may be used for the contacts, also depending on the implementation.

Claims

1. A radio frequency identification, RFID, adaptor for providing tamper detection of a cable seal, wherein the adapter (132) is configured and shaped for coupling to a cable seal (100) of the type including an electrically conducting cable (102) and a body (104), the body (104) including a pair of seal bores (106) extending there through, wherein each seal bore (106) includes a one-way lock (108) configured to allow a corresponding end of the cable (102) to be inserted through the seal bore (106) and inhibit their removal therefrom,

the RFID adaptor comprising:

a cup-shaped (132) housing with a u-shaped cross section and configured for receiving the cable seal (100) in the housing (132), the housing (132) comprising a cable hole (133) in a closed end thereof;

an insert (134) positioned within the housing (132), the insert 8134) comprising a blind channel (135a) and a through channel (135b), wherein the blind channel (135a) terminates within the insert (134), and the through channel (135b) passes though the insert (134), and wherein the through channel (135b) is configured to be aligned with the cable hole (133); and

an RFID tag (136) positioned proximal the insert (134), the RFID tag comprising a pair of electrical contacts (137), each contact comprising at least one cut (141) to allow a conductive portion of the cable (102) from the cable seal (100) to pass there through, wherein each contact (137) is configured to be aligned with a corresponding one of the blind channel (135a) and the through channel (135b) for establishing electrical connections by the contacts, respectively, to a first portion of the cable in the blind channel (135a) and a second portion of the cable (102) in the through channel (135b); wherein the RFID tag (136) is configured for determining whether the cable is intact or not by determining electrical conduction through the cable (102) and configured for indicating this by transmission of an RFID signal.

2. The RFID adaptor of claim 1, wherein the RFID tag comprises two circuits which are electrically isolated from each other when the cable seal is open and electrically connected through the contacts (137) and the cable (102) the when the cable seal is closed, wherein the RFID tag transmits an identification signal only when the cable seal is closed and the two contacts are electrically connected through the cable (102).

3. The RFID adaptor of anyone of the preceding claims, wherein the RFID tag further comprises an Application-Specific Integrated Circuit (ASIC) configured to measure the resistance of the cable.

4. The RFID adaptor of claim 3, wherein the RFID tag is configured to transmit an identification signal including a tamper bit indicating whether the measured resistance falls within a predefined range.

5. The RFID adaptor of claim 4, wherein the identification signal includes a representation of the measured resistance.

6. The RFID adaptor of anyone of the claims 3-5, further comprising a third contact position proximal the cable hole and configured to be aligned with the through channel and further comprising a battery configured to activate the ASIC, wherein the ASIC is only activated when the cable has been passed through all three contacts.

7. The RFID adapter of anyone of the preceding claims, wherein the RFID adapter is configured for using the cable (102) as part of a radio antenna.

8. The RFID adaptor of claim 7, wherein a position and length of the cable controls radio sensitivity for the antenna and transmit power of the RFID tag.

9. The RFID adaptor of anyone of the preceding claims, further comprising a pressure layer (140) positioned between the RFID tag (136) and the insert (134), the pressure layer comprising a pair of cuts (141) configured to be aligned with the contacts (137) of the RFID tag, the pressure layer (140) allowing the cable (102) to pass through the pair of cuts (141) while deforming the pressure layer (140), the pressure layer being configured for reinforcing or maintaining the physical connection between the con- tacts (137) and the cable (102).

10 The RFID adaptor of any preceding claim, further comprising a pressure layer (140) positioned between the RFID tag (136) and the insert (134), the pressure layer comprising a pair of cuts (141) configured to be aligned with the contacts (137) of the RFID tag; wherein the RFID tag (136) comprises a flexible Ultra High Frequency (UHF) RFID inlay, wherein the RFID inlay is configured in two electrically isolated circuits, each circuit comprising one of the contacts (137); wherein the RFID inlay is larger than the cross section of the housing (132) and folded into three portions with a first side portion positioned along a first side of the insert (134) between the insert (134) and the housing (132), a middle portion positioned adjacent the pressure layer (140), and a second side portion positioned along a second, opposing side of the insert (134) between the insert (134) and the housing (132), wherein the contacts (137) are positioned in the middle portion in alignment with the cuts (141) of the pressure layer (140).

11. The RFID adaptor of claim 9 or 10, wherein the pressure layer comprises closed cell foam or rubber.

12. The RFID adaptor of any preceding claim, further comprising a weather- protective layer (138) positioned adjacent the RFID tag (136) on a side of the RFID tag distal from the insert (134).

13. The RFID adaptor of claim 12, wherein the protective layer (138) comprises a gel.

14. The RFID adaptor according to claim 1, wherein the RFID tag comprises a single circuit configured to transmit an identification signal along with a tamper bit, the tamper bit indicating whether the cable is intact or has been compromised.

15. The RFID adaptor of claim 14, wherein the RFID tag is configured detect whether the cable is intact, reset the tamper bit if the cable is intact, and set the tamper bit if the cable has been compromised.

16. The RFID adaptor of claim 15, wherein the RFID tag further comprises an electronic latch to store the tamper bit once it is determined that the cable has been compromised, wherein the storage of the tamper bit is configured for not being affected by a subsequent re-establishment of the integrity of the cable (102) and electrical connection between the contacts (137).

17. The RFID adaptor of claim 16, wherein the RFID tag further comprises a latch to store the tamper bit once the tamper bit has been set.

18. An RFID adaptor according to any preceding claim in combination with cable a seal (100) of the type including an electrically conducting cable (102) and a body (104), the body (104) including a pair of seal bores (106) extending vertically there through, wherein each seal bore (106) includes a one-way lock (108) configured to allow a corresponding end of the cable (102) to be inserted through the seal bore (106) and inhibit their removal therefrom.