User verification systems and methods

A method for managing the distribution of content performed by a user verification system comprising a processor and a non-transitory computer readable storage medium storing instructions that, when executed by the processor, cause the processor to perform a method comprising:

• receiving one or more one messages from a first device, the one or more messages comprising at least a first signed message received by the first device from a second device, the at least a first signed message being signed using a first private key associated with the second device, the one or more messages further comprising at least a second signed message received by the first device from a third device, the at least a second signed message being signed using a second private key associated with the third device, the second device and the third device being different devices than the first device, wherein possession of the at least a first signed message and the at least a second signed message by the first device provides an indication of a relative likelihood that the user of the first device is a human user;
• generating, based on the one or more messages received from the first device, a Turing score associated with the user of the first device, the Turing score indicating the relative likelihood that the user of the first device is a human user;
• receiving a content item for distribution, the content item being associated with at least one content parameter specifying a threshold Turing score associated with the content item;
• determining that the generated Turing score meets the threshold Turing score specified in the at least one content parameter;
• and
• transmitting, based on the determination, the content item to the first device.