Providing and using an activity logging service

A method comprising:

• linking, by an activity logging service hosted on a manager device comprising a gateway device, the activity logging service with a hash ledger storage service that is hosted by a server computer that operates on a network, wherein the manager device communicates with the server computer via the network, wherein the activity logging service is configured to collect event data from an observer device that communicates with the manager device, to generate an activity log based on the event data, and to send a hash of the activity log to the hash ledger storage service, wherein the hash ledger storage service is configured to store a hash ledger that comprises a hashed version of the activity log, wherein the activity log represents events that are associated with a user device that is associated with an entity and that were observed by the observer device;
• detecting, by the manager device, a request to search an area around the manager device and the user device for observer devices that are capable of detecting the events that are associated with the user device, the observer devices comprising the observer device and the events comprising an event, wherein the request to search the area is created at the user device, and wherein the observer device comprises a camera, and wherein the camera observes activity of the user device to capture the event;
• in response to detecting the request, scanning, by the manager device, the area around the manager device and the user device for the observer devices, wherein results of the scanning are presented in an observer device registration window presented at the user device, and wherein the observer device registration window comprises an option to use the observer device to detect the event;
• in response to detecting selection of the option to use the observer device to detect the event, linking and configuring, by the manager device, the observer device with the activity logging service, wherein the manager device configures the observer device to detect the event, to determine an identity associated with the event based on a device identifier associated with the user device, to generate the event data, and to provide the event data to the activity logging service via the network, wherein the event data describes the event;
• generating, by the manager device and based on event data that the manager device obtains from the observer device, a block that represents the event, wherein the block comprises first data that represents the identity, second data that describes the event, and third data that defines a time the observer device observed the event;
• adding, by the manager device, the block to the activity log that represents activities associated with the entity, wherein the activity log comprises a previous block that represents a previous event associated with the user device;
• hashing, by the manager device, a portion of the activity log that comprises the block and the previous block to generate the hash;
• and
• sending, by the manager device and to the server computer via the network, the hash to the hash ledger storage service, wherein the hash ledger storage service appends the hash of the portion of the activity log to the hash ledger that comprises the hashed version of the activity log for the entity to create an updated hash ledger comprising an updated hashed version of the activity log, and wherein the hash ledger service stores the hash ledger as a blockchain data structure that is stored at the server computer, whereby the activity log cannot be modified without detection.

A computer storage medium having computer-executable instructions stored thereon that, when executed by a processor, cause the processor to perform operations comprising:

• linking, by an activity logging service hosted on a manager device comprising a gateway device, the activity logging service with a hash ledger storage service that is hosted by a server computer that operates on a network, wherein the manager device communicates with the server computer via the network, wherein the activity logging service is configured to collect event data from an observer device that communicates with the manager device, to generate an activity log based on the event data, and to send a hash of the activity log to the hash ledger storage service, wherein the hash ledger storage service is configured to store a hash ledger that comprises a hashed version of the activity log, wherein the activity log represents events that are associated with a user device that is associated with an entity and that were observed by the observer device;
• detecting, by the manager device, a request to search an area around the manager device and the user device for observer devices that are capable of detecting the events that are associated with the user device, the observer devices comprising the observer device and the events comprising an event, wherein the request to search the area is created at the user device, and wherein the observer device comprises a camera, and wherein the camera observes activity of the user device to capture the event;
• in response to detecting the request, scanning, by the manager device, the area around the manager device and the user device for the observer devices, wherein results of the scanning are presented in an observer device registration window presented at the user device, and wherein the observer device registration window comprises an option to use the observer device to detect the event;
• in response to detecting selection of the option to use the observer device to detect the event, linking and configuring, by the manager device, the observer device with the activity logging service, wherein the manager device configures the observer device to detect the event, to determine an identity associated with the event based on a device identifier associated with the user device, to generate the event data, and to provide the event data to the activity logging service via the network, wherein the event data describes the event;
• generating, by the manager device and based on event data that the manager device obtains from the observer device, a block that represents the event, wherein the block comprises first data that represents the identity, second data that describes the event, and third data that defines a time the observer device observed the event;
• adding, by the manager device, the block to the activity log that represents activities associated with the entity, wherein the activity log comprises a previous block that represents a previous event associated with the user device;
• hashing, by the manager device, a portion of the activity log that comprises the block and the previous block to generate the hash;
• and
• sending, by the manager device and to the server computer via the network, the hash to the hash ledger storage service, wherein the hash ledger storage service appends the hash of the portion of the activity log to the hash ledger that comprises the hashed version of the activity log for the entity to create an updated hash ledger comprising an updated hashed version of the activity log, and wherein the hash ledger service stores the hash ledger as a blockchain data structure that is stored at the server computer, whereby the activity log cannot be modified without detection.