Abstract: Example implementations relate to tangible resources. For example, a method includes receiving, at a computer, a cumulative consumption value of a tangible resource from a device that consumes the tangible resource. The method also includes calculating a plurality of variable values by way of the cumulative consumption value, a statistically derived depletion quantity of the tangible resource, and an estimated time to ship a supply of replacement tangible resource to the device to form calculated variable values such that the calculating is performed at least in part by the computer. The method further includes causing the supply of replacement tangible resource to be shipped to the device in accordance with the calculating.

Abstract: Example embodiments relate to updating key pairs based on digital signature states. In example embodiments, first credentials that are generated using a first private key may be sent to a user computing device, where the first private key is associated with a first public key. At some stage, second credentials that are generated using the first private key and a second private key are sent to the user computing device, where the second credentials specify that the first private key is deprecated, and where the user computing device authenticates the second credentials using the first public key. In response to receiving confirmation that a firmware upgrade is installed a number of user computing devices such that an upgrade threshold is satisfied, the first private key may be deactivated. The firmware upgrade may be provided in response to receiving a firmware upgrade request from the user computing device.

Abstract: A method performed using a computer includes receiving a cumulative consumption value for a printing fluid corresponding to a supply from a printer at the computer. The method also includes calculating a plurality of variable values by way of the cumulative consumption value for the printing fluid, a statistically derived depletion quantity for the printing fluid, and an estimated time to ship a supply of replacement printing fluid to the printer to form calculated variable values. The method also includes causing the supply of replacement printing fluid to be shipped to the printer in accordance with the calculating.