WO2023161188A1

WO2023161188A1 - Communicating a media stream between a guest device and an approval device for evaluating whether to unlock an electronic lock

Info

Publication number: WO2023161188A1
Application number: PCT/EP2023/054204
Authority: WO
Inventors: Fredrik Einberg
Original assignee: Assa Abloy Ab
Priority date: 2022-02-22
Filing date: 2023-02-20
Publication date: 2023-08-31

Abstract

It is provided a method for communicating a media stream between a guest device (1) and an approval device (2) for evaluating whether to unlock an electronic lock (12). The method comprises: obtaining (40) a pointer to the coordination server (3) for establishing contact with the approval device (2); connecting (41 ) to the coordination server (3); establishing (42) a peer-to-peer connection between the guest device (1) and the approval device (2); providing (43) a media stream to the approval device (2) over the peer-to-peer connection; receiving (53) the media stream from the guest device (1) over the peer-to-peer connection; presenting (44) the media stream to an approval user (6); receiving (45) user input indicating to unlock the electronic lock (12); providing (46) a first unlock signal to unlock the electronic lock; and transmitting (47) the first unlock signal to unlock the electronic lock (12).

Description

COMMUNICATING A MEDIA STREAM BETWEEN A GUEST DEVICE AND AN APPROVAL DEVICE FOR EVALUATING WHETHER TO UNLOCK AN

ELECTRONIC LOCK

TECHNICAL FIELD

[0001] The present disclosure relates to the field of communication between a guest device and an approval device for evaluating whether to unlock an electronic lock.

BACKGROUND

[0002] There are now doorbells that include cameras and microphones, allowing a homeowner to see and/or hear the person at the door, e.g. from an application (also known as ‘app’) on a smartphone. This increases security and peace of mind for the homeowner.

[0003] However, current doorbell video solutions require that media capturing hardware, such as a camera and/or microphone, is installed. This maybe inconvenient and drives cost. Moreover, there is a privacy concern of passers-by, since the camera/microphone is always there, and the passers-by do not know if the media capturing hardware is active or not.

SUMMARY

[0004] One object is to provide a solution for communicating a media stream to allow an approval user to evaluate whether to unlock an electronic lock.

[0005] According to a first aspect, it is provided a method for communicating a media stream between a guest device and an approval device for evaluating whether to unlock an electronic lock. The method is performed by a system comprising a coordination server, the guest device, and the approval device, The method comprises: obtaining, by the guest device, a pointer to the coordination server for establishing contact with the approval device, wherein the pointer is associated with the electronic lock; connecting, by the guest device, to the coordination server based on the pointer; establishing, by the coordination server, the guest device and the approval device, a peer-to-peer connection between the guest device and the approval device, under coordination by the coordination server; providing, by the guest device, a media stream to the approval device over the peer-to-peer connection; receiving, by the approval device, the media stream from the guest device over the peer-to-peer connection; presenting, by the approval device, the media stream to an approval user, being a user of the approval device; receiving, by the approval device, user input indicating to unlock the electronic lock; providing, by the approval device, a first unlock signal to unlock the electronic lock; and transmitting, by the approval device, the first unlock signal to unlock the electronic lock.

[0006] According to a second aspect, it is provided a method for communicating a media stream between a guest device and an approval device for evaluating whether to unlock an electronic lock. The method is performed by the guest device. The method comprises: obtaining a pointer to a coordination server for establishing contact with the approval device, wherein the pointer is associated with the electronic lock; connecting to the coordination server based on the pointer; establishing a peer-to-peer connection to the approval device, under coordination by the coordination server; and providing a media stream to the approval device over the peer-to-peer connection.

[0007] The obtaining a pointer may comprise reading a near-field communication, NFC, tag comprising the pointer.

[0008] The obtaining a pointer may comprise reading an optical code comprising the pointer.

[0009] The method may further comprise: receiving a first unlock signal from the approval device.

[0010] The first unlock signal may comprise a personal identification number, PIN. In this case, the method further comprises: presenting the PIN to a guest, being a user of the guest device.

[0011] The method may further comprise: transmitting a second unlock signal to the electronic lock, wherein the second unlock signal is based on the first unlock signal. [0012] The peer-to-peer connection may be a web real-time-communication, WebRTC, connection.

[0013] According to a third aspect, it is provided a guest device for communicating a media stream between the guest device and an approval device for evaluating whether to unlock an electronic lock. The guest device comprises: a processor; and a memory storing instructions that, when executed by the processor, cause the guest device to: obtain a pointer to a coordination server for establishing contact with the approval device, wherein the pointer is associated with the electronic lock; connect to the coordination server based on the pointer; establish a peer-to-peer connection to the approval device, under coordination by the coordination server; and provide a media stream to the approval device over the peer-to-peer connection.

[0014] The guest device may be a smartphone.

[0015] According to a fourth aspect, it is provided a computer program for communicating a media stream between a guest device and an approval device for evaluating whether to unlock an electronic lock. The computer program comprises computer program code which, when executed on the guest device causes the guest device to: obtain a pointer to a coordination server for establishing contact with the approval device, wherein the pointer is associated with the electronic lock; connect to the coordination server based on the pointer; establish a peer-to-peer connection to the approval device, under coordination by the coordination server; and provide a media stream to the approval device over the peer-to-peer connection.

[0016] According to a fifth aspect, it is provided a computer program product comprising a computer program according to the fourth aspect and a computer readable means comprising non-transitory memory in which the computer program is stored.

[0017] According to a sixth aspect, it is provided a method for communicating a media stream between a guest device and an approval device for evaluating whether to unlock an electronic lock. The method is performed by the approval device. The method comprises: establishing a peer-to-peer connection to the guest device under coordination by the coordination server; receiving a media stream from the guest device over the peer-to-peer connection; presenting the media stream to an approval user, being a user of the approval device; receiving user input indicating to unlock the electronic lock; providing a first unlock signal to unlock the electronic lock; and transmitting the first unlock signal to unlock the electronic lock.

[0018] The providing a first unlock signal may comprise obtaining credential data that is usable to unlock the electronic lock. In this case, the first unlock signal comprises the credential data.

[0019] The credential data may be a personal identification number, PIN, In this case, the transmitting the first unlock signal may comprise transmitting the first unlock signal to the guest device for presenting the PIN to a guest, being a user of the guest device.

[0020] The credential data may be a cryptographically protected data item. In this case, the transmitting the first unlock signal comprises transmitting the first unlock signal to the electronic lock.

[0021] The peer-to-peer connection may be a web real-time-communication, WebRTC, connection.

[0022] According to a seventh aspect, it is provided an approval device for communicating a media stream between a guest device and the approval device for evaluating whether to unlock an electronic lock. The approval device comprises: a processor; and a memory storing instructions that, when executed by the processor, cause the approval device to: establish a peer-to-peer connection to the guest device under coordination by the coordination server; receive a media stream from the guest device over the peer-to-peer connection; present the media stream to an approval user, being a user of the approval device; receive user input indicating to unlock the electronic lock; provide a first unlock signal to unlock the electronic lock; and transmit the first unlock signal to unlock the electronic lock.

[0023] According to an eighth second aspect, it is provided a computer program for communicating a media stream between a guest device and the approval device for evaluating whether to unlock an electronic lock. The computer program comprises computer program code which, when executed on the approval device causes the approval device to: establish a peer-to-peer connection to the guest device under coordination by the coordination server; receive a media stream from the guest device over the peer-to-peer connection; present the media stream to an approval user, being a user of the approval device; receive user input indicating to unlock the electronic lock; provide a first unlock signal to unlock the electronic lock; and transmit the first unlock signal to unlock the electronic lock.

[0024] According to a ninth aspect, it is provided a computer program product comprising a computer program according to the eighth aspect and a computer readable means comprising non-transitory memory in which the computer program is stored.

[0025] Generally, all terms used in the claims are to be interpreted according to their ordinary meaning in the technical field, unless explicitly defined otherwise herein. All references to "a/an/the element, apparatus, component, means, step, etc." are to be interpreted openly as referring to at least one instance of the element, apparatus, component, means, step, etc., unless explicitly stated otherwise. The steps of any method disclosed herein do not have to be performed in the exact order disclosed, unless explicitly stated.

BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Aspects and embodiments are now described, by way of example, with reference to the accompanying drawings, in which:

[0027] Fig 1 is a schematic diagram illustrating an environment in which embodiments presented herein can be applied;

[0028] Fig 2 is a swim-lane diagram illustrating embodiments of methods for communicating a media stream between a guest device and an approval device for evaluating whether to unlock an electronic lock;

[0029] Fig 3 is a schematic diagram illustrating components of the guest device, the approval device and the coordination server of Fig 1 according to one embodiment; and [0030] Fig 4 shows one example of a computer program product comprising computer readable means.

DETAILED DESCRIPTION

[0031] The aspects of the present disclosure will now be described more fully hereinafter with reference to the accompanying drawings, in which certain embodiments of the invention are shown. These aspects may, however, be embodied in many different forms and should not be construed as limiting; rather, these embodiments are provided by way of example so that this disclosure will be thorough and complete, and to fully convey the scope of all aspects of invention to those skilled in the art. Like numbers refer to like elements throughout the description.

[0032] Embodiments presented herein provide an improved way to enable an approval user to approve an electronic lock to be unlocked. Specifically, a guest device first obtains a pointer (e.g. URI (uniform resource indicator)) to a coordination server, e.g. using a QR (quick response) code, NFC (near-field communication) tag, or an alphanumeric string, wherein the pointer is associated with the electronic lock that the guest would like to unlock. A peer-to-peer connection is established between the guest device and an approval device, under coordination of the coordination server. A media stream (comprising video and/ or audio) is then provided from the guest device to the approval device over the peer-to-peer connection. The approval user can thereby evaluate whether to unlock the lock and triggers an unlock when this is approved. The media stream is captured by the guest device, whereby there is no need for a fixed camera and/ or microphone to be provided by the electronic lock. Moreover, by using the pointer to connect to the coordination server, the guest device does not need to have any special software installed for this solution; it is sufficient to be able to obtain the pointer and to set up the peer-to-peer connection with the approval device via a mobile web browser. Alternatively, the pointer could direct user to install or open a preinstalled a mobile app that subsequently is used to establish the peer-to-peer connection. Hence, a solution is provided that is easily deployed since no expensive or complicated hardware or software is required at the electronic lock or the guest device. [0033] Fig 1 is a schematic diagram illustrating an environment in which embodiments presented herein can be applied. Access to a restricted physical space 16 is restricted by a door 15 which is selectively unlockable using an electronic lock 12. The door 15 stands between the restricted physical space 16 and an accessible physical space 14. Note that the accessible physical space 14 can be a restricted physical space in itself, but in relation to the door 15, the accessible physical space 14 is accessible. The function of the door 15 could alternatively be achieved using a gate, hatch, cabinet door, drawer, window, etc. The electronic lock 12 is provided in order to control access to the restricted physical space 16, by selectively unlocking the door 15.

[0034] The electronic lock 12 can be provided in a structure 17 (such as a wall) surrounding the door 15 (as shown) or the electronic lock 12 can be provided in the door 15 itself (not shown). The electronic lock 12 is controllable to be in a locked state or in an unlocked state.

[0035] An approval user 6 is associated with an approval device 2. The approval user 6 is authorised to unlock the electronic lock 12. A guest 5 carries a guest device 1. The guest 5 wants to pass through the door 15 to gain access to the restricted physical space 16.

[0036] The approval device 2 and the guest device 1 are implemented using any suitable electronic devices that can perform the functions described herein. For instance, the approval device 2 and the guest device 1 can be implemented in a smartphone, wearable device (e.g. smart watch, smart jewellery), traditional mobile phone, tablet computer, or even a general-purpose computer (especially for the approval device) etc.

[0037] A coordination server 3 is provided which can communicate with the guest device 1 and the approval device 2. The coordination server 3 is implemented as any suitable server (i.e. a computer that is capable to process and respond to requests provided to the server). The communication can occur over a communication network 7, which can be an internet protocol (IP)-based network. The communication network 7 can e.g. comprise any one or more of a local wireless network, a cellular network, a wired local-area network, a wide-area network (such as the Internet), etc. [0038] Collectively, the coordination server 3, the guest device 1 and the approval device 2 make up a system for communicating a media stream between the guest device 1 and the approval device 2 for evaluating whether to unlock the electronic lock 12.

[0039] As explained in more detail below, when the guest would like access to the restricted physical space 16, the guest device 1 obtains a pointer to the coordination server 3 from a pointer indicator 18. The pointer indicator 18 is specific to the electronic lock 12 and can e.g. be provided as a QR code, NFC tag, or a printed alphanumeric string, wherein the pointer comprises a URI to the coordination server. The URI is specific for the electronic lock, either by including an identifier of the electronic lock 12 as a parameter in the URI or enabling identification using a lookup table that maps (at least part of) the URI with the electronic lock 12. When the guest device 1 connects to the coordination server 3 using the URI, the coordination server 3 coordinates the establishment of a peer-to-peer connection (over the communication network 7) between the guest device 1 and the approval device 2 for real-time communication of audio and/ or video. Based on the real-time communication, the approval user 6 can thereby evaluate whether to unlock the electronic lock 12. The approval user 6 can be an owner/tenant of the restricted physical space 16. Alternatively, the approval user can be a central access control function, for which the owner/tenant has given access to unlock the electronic lock 12, e.g. if the owner/tenant has lost a credential for opening the electronic lock 12.

[0040] Fig 2 is a swim-lane diagram illustrating embodiments of methods for communicating a media stream between a guest device 1 and an approval device 2 for evaluating whether to unlock an electronic lock. Various steps are performed each by the guest device 1, the coordination server 3 and the approval device 2. The steps performed by the guest device 1 can be performed by a web browser of the guest device 1 and/or by a software application installed in the guest device 1.

[0041] In an obtain pointer step 40, the guest device obtains a pointer (e.g. URI) to the coordination server 3 for establishing contact with the approval device 2, wherein the pointer is associated with the electronic lock 12. The pointer can be obtained from the pointer indicator 18 described above. Hence, the obtaining a pointer can comprise reading a pointer indicator 18 in the form of an NFC tag comprising the pointer. Alternatively, the obtaining a pointer can comprise reading a pointer indicator 18 comprising an optical code (e.g. QR code or other two-dimensional or one-dimensional optical code) comprising the pointer.

[0042] In a connect to server device step 41, the guest device 1 connects to the coordination server 3 based on the pointer. This can e.g. be performed by a web browser on the guest device connecting to the URI of the pointer.

[0043] In an establish connection step 42, the coordination server 3 coordinates to establish a peer-to-peer connection between the guest device 1 and the approval device 2. The peer-to-peer connection supports peer-to-peer media streaming over the communication network 7 and can e.g. be in the form of a WebRTC (web real-time- communication), connection. Since the pointer is specific to the electronic lock 12, the coordination server can determine the approval device that is associated with the electronic lock 12 in question. It is to be noted that the electronic lock 12 is associated with one or more approval device. An approval device can be associated with a plurality of electronic locks 12.

[0044] By having the pointer associated with the electronic lock 12, there is no fixed relationship between the pointer (by the electronic lock 12) and the approval device 2, i.e. there is no fixed relationship with a specific approval user. Instead, it is the coordination server 3 that maintains the association between each electronic lock 12 and one or more approval devices 2. In this way, the association between approval device 2 and electronic lock can easily be updated by configuring the lookup table that is used by the coordination server 3. Hence, the tag can remain unchanged if there needs to be an update in the association with an approval device, e.g. when there is an ownership change of the asset protected by the electronic lock 12. Moreover, privacy is improved since the approval device 2 cannot be derived from the tag per se without having access to the lookup table.

[0045] In a provide media stream step 43, the guest device 1 provides a media stream 24 to the approval device 2 over the peer-to-peer connection. The media stream comprises video data and/or audio data captured by a camera and/or microphone of the guest device i. The media stream contains audio/video that is captured over time, i.e. not only a single image.

[0046] In a receive media stream step 53, the approval device 2 receives the media stream 24 from the guest device 1 over the peer-to-peer connection.

[0047] By providing the media stream over the peer-to-peer connection, there is no coordination server 3 or any other server that needs to be involved in the media transfer. This greatly improves scalability e.g. compared to a situation where media stream data is transferred via an intermediate server.

[0048] In a present media stream step 44, the approval device 2 presents the media stream 24 received from the guest device 1 to an approval user 6, being a user of the approval device 2. When the media stream comprises video, this implies that the video content is presented to the approval user 6, e.g. on a screen of the approval device 2. When the media stream comprises audio, the audio content is presented to the approval user 6, e.g. using speakers of the approval device 2 and/or using headphones or a sound system connected to the approval device 2.

[0049] Optionally, there is a media stream also in the opposite direction, from the approval device 2 to the guest device 1, over the peer-to-peer communication channel. This allows the approval user 6 to provide instructions to the guest, e.g. to direct the video camera toward the face of the guest, or to direct the camera towards the door to allow visual verification of the guest being by the correct door 15.

[0050] In a receive user input step 45, the approval device 2 receives user input indicating to unlock the electronic lock 12. This can e.g. be received by the user pressing an approval button on a user interface presented on a touch screen of the approval device 2. This user input indicates that the approval user 6 approves access to the restricted physical space for the guest 5.

[0051] In a provide 1^st unlock signal step 46, the approval device 2 provides a first unlock signal to unlock the electronic lock 12. [0052] In one embodiment, this step comprises obtaining credential data that is usable to unlock the electronic lock, and wherein the first unlock signal comprises the credential data.

[0053] The credential data can be in the form of a PIN (personal identification number), e.g. as a sequence of digits. The PIN can be a one-time PIN generated by the approval device or obtained from another device (e.g. a server) that generates the onetime PIN.

[0054] Alternatively, the credential data is a cryptographically protected data item. This can be a data item that is cryptographically signed or encrypted by an entity (e.g. the approval device 2, or a separate access control server) that is trusted by the electronic lock. The protected data item can contain a time and an explicit or implicit (e.g. pre-configured) validity period, to thereby prevent a replay attack.

[0055] In a transmit 1^st unlock signal step 47, the approval device 2 transmits the first unlock signal 26 to unlock the electronic lock 12. When the credential data comprises a PIN, the transmitting 47 the first unlock signal 26 comprises transmitting the first unlock signal to the guest device 1 for presenting the PIN to the guest 5 (being a user of the guest device 1).

[0056] When the credential data comprises the cryptographically protected data item, the transmitting 47 the first unlock signal comprises transmitting the first unlock signal 26 to the electronic lock 12. In this case, the first unlock signal 26 can be transmitted to the electronic lock 12 via the guest device 1 (e.g. over the peer-to-peer communication channel) or without the use of the guest device, e.g. using local communication (such as Bluetooth, BLE (Bluetooth Low Energy), or Wi-Fi) and/ or over the communication network 7.

[0057] In an optional receive 1^st unlock signal step 48, the guest device 1 receives the first unlock signal 26 from the approval device 2. Depending on whether the first unlock signal comprises a PIN or a cryptographically protected data item, the method proceeds to an optional present PIN step 49 or an optional transmit 2^nd unlock signal step 50. [0058] When the credential data comprises a PIN, the guest device 1, in the optional present PIN step 49, presents the PIN to the guest 5 (being a user of the guest device 1). For instance, the PIN can be rendered on a screen of the guest device 1, allowing the guest to enter the PIN on a keypad of the electronic lock 12 to gain access.

[0059] When the credential data comprises the cryptographically protected data item, the guest device 1, in the optional transmit 2^nd unlock signal step 50, transmits a second unlock signal to the electronic lock 12. The second unlock signal is based on the first unlock signal, e.g. by comprising the cryptographically protected data item. By routing the communication of the cryptographically protected data item via the guest device, the electronic lock 12 only needs to have local communication abilities and can otherwise be an offline device.

[0060] Using embodiment presented herein, the media stream is obtained by the guest device rather than fixed, mounted media capturing hardware, whereby there is no need for a fixed camera and/or microphone by the electronic lock. Moreover, by using the pointer to connect to the coordination server, the guest device does not need to have any special software installed for this solution; it is sufficient to be able to obtain the pointer and to set up the peer-to-peer connection with the approval device. Hence, a solution is provided that is easily deployed since no expensive or complicated hardware or software is required at the electronic lock or the guest device. This makes the solution easy to deploy as a retrofit solution to provide media-stream based access evaluation for the approval user. Additionally, since there is no media capturing hardware (such as a camera and/ or microphone) mounted by the electronic lock, a privacy is conserved around the electronic lock compared to when media capturing hardware is mounted by the electronic lock.

[0061] Fig 3 is a schematic diagram illustrating components of the guest device 1, the approval device 2 and/or the coordination server 3 of Fig 1 according to one embodiment. A processor 60 is provided using any combination of one or more of a suitable central processing unit (CPU), graphics processing unit (GPU), multiprocessor, microcontroller, digital signal processor (DSP), etc., capable of executing software instructions 67 stored in a memory 64, which can thus be a computer program product. The processor 60 could alternatively be implemented using an application specific integrated circuit (ASIC), field programmable gate array (FPGA), etc. The processor 60 can be configured to execute the method described with reference to Fig 2 above.

[0062] The memory 64 can be any combination of random-access memory (RAM) and/or read-only memory (ROM). The memory 64 also comprises non-transitory persistent storage, which, for example, can be any single one or combination of magnetic memory, optical memory, solid-state memory or even remotely mounted memory.

[0063] A data memory 66 is also provided for reading and/ or storing data during execution of software instructions in the processor 60. The data memory 66 can be any combination of RAM and/or ROM.

[0064] An 1/ O interface 62 for communicating with external and/ or internal entities. Optionally, the I/O interface 62 also includes a user interface.

[0065] Other components of the guest device 1, the approval device 2 and the coordination server 3 are omitted in order not to obscure the concepts presented herein.

[0066] Fig 4 shows one example of a computer program product 90 comprising computer readable means. On this computer readable means, a computer program 91 can be stored in a non-transitory memory. The computer program can cause a processor to execute a method according to embodiments described herein. In this example, the computer program product is in the form of a removable solid-state memory, e.g. a Universal Serial Bus (USB) drive. As explained above, the computer program product could also be embodied in a memory of a device, such as the computer program product 64 of Fig 3. While the computer program 91 is here schematically shown as a section of the removable solid-state memory, the computer program can be stored in any way which is suitable for the computer program product, such as another type of removable solid-state memory, or an optical disc, such as a CD (compact disc), a DVD (digital versatile disc) or a Blu-Ray disc.

[0067] The aspects of the present disclosure have mainly been described above with reference to a few embodiments. However, as is readily appreciated by a person skilled in the art, other embodiments than the ones disclosed above are equally possible within the scope of the invention, as defined by the appended patent claims. Thus, while various aspects and embodiments have been disclosed herein, other aspects and embodiments will be apparent to those skilled in the art. The various aspects and embodiments disclosed herein are for purposes of illustration and are not intended to be limiting, with the true scope and spirit being indicated by the following claims.

Claims

1. A method for communicating a media stream between a guest device (i) and an approval device (2) for evaluating whether to unlock an electronic lock (12), the method being performed by a system (10) comprising a coordination server (3), the guest device (1), and the approval device (2), the method comprising: obtaining (40), by the guest device (1), a pointer to the coordination server (3) for establishing contact with the approval device (2), wherein the pointer is associated with the electronic lock (12); connecting (41), by the guest device (1), to the coordination server (3) based on the pointer; establishing (42), by the coordination server (3), the guest device (1) and the approval device (2), a peer-to-peer connection between the guest device (1) and the approval device (2), under coordination by the coordination server (3); providing (43), by the guest device (1), a media stream to the approval device (2) over the peer-to-peer connection; receiving (53), by the approval device (2), the media stream from the guest device (1) over the peer-to-peer connection; presenting (44), by the approval device (2), the media stream to an approval user (6), being a user of the approval device (2); receiving (45), by the approval device (2), user input indicating to unlock the electronic lock (12); providing (46), by the approval device (2), a first unlock signal to unlock the electronic lock; and transmitting (47), by the approval device (2), the first unlock signal to unlock the electronic lock (12).

2. A method for communicating a media stream between a guest device (1) and an approval device (2) for evaluating whether to unlock an electronic lock (12), the method being performed by the guest device (1), the method comprising: obtaining (40) a pointer to a coordination server (3) for establishing contact with the approval device (2), wherein the pointer is associated with the electronic lock (12); connecting (41) to the coordination server (3) based on the pointer; establishing (42) a peer-to-peer connection to the approval device (2), under coordination by the coordination server (3); and providing (43) a media stream to the approval device (2) over the peer-to-peer connection.

3. The method according to claim 2, wherein the obtaining (40) a pointer comprises reading a near-field communication, NFC, tag comprising the pointer.

4. The method according to claim 2, wherein the obtaining (40) a pointer comprises reading an optical code comprising the pointer.

5. The method according to any one of claims 2 to 4, further comprising: receiving (48) a first unlock signal from the approval device (2).

6. The method according to claim 5, wherein the first unlock signal comprises a personal identification number, PIN; and wherein the method further comprises: presenting (49) the PIN to a guest (5), being a user of the guest device.

7. The method according to claim 5, further comprising: transmitting (50) a second unlock signal to the electronic lock, wherein the second unlock signal is based on the first unlock signal.

8. The method according to any one of claims 2 to 7, wherein the peer-to-peer connection is a web real-time-communication, WebRTC, connection.

9. A guest device (1) for communicating a media stream between the guest device (1) and an approval device (2) for evaluating whether to unlock an electronic lock (12), the guest device (1) comprising: a processor (60); and a memory (64) storing instructions (67) that, when executed by the processor, cause the guest device (1) to: obtain a pointer to a coordination server (3) for establishing contact with the approval device (2), wherein the pointer is associated with the electronic lock (12); connect to the coordination server (3) based on the pointer; establish a peer-to-peer connection to the approval device (2), under coordination by the coordination server (3); and provide a media stream to the approval device (2) over the peer-to-peer connection.

10. The guest device (1) according to claim 9, wherein the guest device is a smartphone.

11. A computer program (67, 91) for communicating a media stream between a guest device (1) and an approval device (2) for evaluating whether to unlock an electronic lock (12), the computer program comprising computer program code which, when executed on the guest device (1) causes the guest device (1) to: obtain a pointer to a coordination server (3) for establishing contact with the approval device (2), wherein the pointer is associated with the electronic lock (12); connect to the coordination server (3) based on the pointer; establish a peer-to-peer connection to the approval device (2), under coordination by the coordination server (3); and provide a media stream to the approval device (2) over the peer-to-peer connection.

12. A computer program product (64, 90) comprising a computer program according to claim 11 and a computer readable means comprising non-transitory memory in which the computer program is stored.

13. A method for communicating a media stream between a guest device (1) and an approval device (2) for evaluating whether to unlock an electronic lock (12), the method being performed by the approval device (2), the method comprising: establishing (42) a peer-to-peer connection to the guest device (1) under coordination by the coordination server (3); receiving (53) a media stream from the guest device (1) over the peer-to-peer connection; presenting (44) the media stream to an approval user (6), being a user of the approval device (2); receiving (45) user input indicating to unlock the electronic lock (12); providing (46) a first unlock signal to unlock the electronic lock; and transmitting (47) the first unlock signal to unlock the electronic lock (12).

14- The method according to claim 13, wherein the providing (46) a first unlock signal comprises obtaining credential data that is usable to unlock the electronic lock, and wherein the first unlock signal comprises the credential data.

15. The method according to claim 13, wherein the credential data is a personal identification number, PIN, and wherein the transmitting (47) the first unlock signal comprises transmitting the first unlock signal to the guest device for presenting the PIN to a guest (5), being a user of the guest device.

16. The method according to claim 13, wherein the credential data is a cryptographically protected data item, and wherein the transmitting (47) the first unlock signal comprises transmitting the first unlock signal to the electronic lock (12).

17. The method according to any one of claims 13 to 16, wherein the peer-to-peer connection is a web real-time-communication, WebRTC, connection.

18. An approval device (2) for communicating a media stream between a guest device (1) and the approval device (2) for evaluating whether to unlock an electronic lock (12), the approval device (2) comprising: a processor (60); and a memory (64) storing instructions (67) that, when executed by the processor, cause the approval device (2) to: establish a peer-to-peer connection to the guest device (1) under coordination by the coordination server (3); receive a media stream from the guest device (1) over the peer-to-peer connection; present the media stream to an approval user (6), being a user of the approval device (2); receive user input indicating to unlock the electronic lock (12); provide a first unlock signal to unlock the electronic lock; and transmit the first unlock signal to unlock the electronic lock (12).

19. A computer program (67, 91) for communicating a media stream between a guest device (1) and the approval device (2) for evaluating whether to unlock an electronic lock (12), the computer program comprising computer program code which, when executed on the approval device (2) causes the approval device (2) to: establish a peer-to-peer connection to the guest device (1) under coordination by the coordination server (3); receive a media stream from the guest device (1) over the peer-to-peer connection; present the media stream to an approval user (6), being a user of the approval device (2); receive user input indicating to unlock the electronic lock (12); provide a first unlock signal to unlock the electronic lock; and transmit the first unlock signal to unlock the electronic lock (12).

20. A computer program product (64, 90) comprising a computer program according to claim 19 and a computer readable means comprising non-transitory memory in which the computer program is stored.