Abstract: Systems and methods include receiving from a keyless account service, in response to an authentication request, a keyless account service signature including a cryptographic signature over a user identifier, a managing application identifier of a managing application, a nonce and to-be-revealed data, where the managing application manages activities by the user on a blockchain, and where the nonce is populated with a public key associated with the authentication request. An activity signature is generated for a particular activity based on the keyless account service signature and at least one to-be-revealed data field associated with the to-be-revealed data of the authentication request.

Abstract: A multi-position micro-fluidic valve system that includes an actuator assembly with a housing and a drive shaft rotatably disposed in the housing for rotational displacement about a drive axis thereof. One end of the drive shaft is configured to couple to a drive motor for selective rotation of the drive shaft about the drive axis. One of at least two different multi-position fluid valve devices can be removably mated to the actuator assembly. Each valve device is configured for rotational movement of a corresponding valve shaft about a valve rotational axis thereof between a plurality of discrete fluid distribution positions. A coupling device selectively and removably mounts the valve shaft of the respective valve device to the drive shaft of the actuator assembly. This enables selective positioning of the multi-position fluid valve device at a discrete one of the plurality for discrete distribution positions.

Abstract: A liquid dispensing system is provided for automated dispensing of a plurality of liquid reagents into a recreational body of water. The liquid dispensing system includes a cartridge apparatus defining a cavity, and a cartridge front wall. A plurality of liquid reagent containers are included, each containing a respective liquid reagent and each being disposed in the cavity in a manner permitting access to each respective liquid reagent through the front wall. A docking assembly is provided having a dock manifold device, and is releasably coupled to the cartridge apparatus between a first condition and a second condition. In a first condition, the cartridge apparatus can be removably coupled to the docking assembly, while in the second condition, the cartridge apparatus is lockably mounted to the docking assembly in a manner permitting fluid communication through the cartridge front wall from the respective reagent container to respective fluid passages of the manifold device.