System and method for privacy-preserving data retrieval for connected power tools

A method for network-connected power tool operation with user anonymity comprising:

• generating, with a processor in a power tool, a plurality of linked cryptographic keys using a first secret cryptographic key stored in a memory in the power tool and a one-way function, the generating further comprising:
• generating each linked cryptographic key in the plurality of linked cryptographic keys based on an output of the one-way function applied to a previous linked cryptographic key in the plurality of linked cryptographic keys in a predetermined order starting with the first secret cryptographic key until generating a final linked cryptographic key in the plurality of linked cryptographic keys;
• generating, with the processor, a first encrypted serial number for the power tool based on an output of an encryption function using the final linked cryptographic key applied to a non-encrypted serial number for the power tool stored in the memory;
• generating, with the processor, usage data based on data received from at least one sensor in the power tool during operation of the power tool;
• and
• transmitting, with a network device in the power tool, the usage data in association only with the first encrypted serial number to a maintenance system to enable usage data collection that prevents identification of the power tool as being associated with the usage data.

A power tool configured for anonymized network-connected operation comprising:

• at least one sensor;
• a memory configured to store:
• a non-encrypted serial number;
• a first cryptographic key;
• and
• usage data;
• a network device;
• and
• a processor operatively connected to the at least one sensor, the memory, and the network device, the processor being configured to:
• generate the first cryptographic key that is stored in a memory in the power tool;
• generate a first encrypted serial number for the power tool based on an output of an encryption function using the first cryptographic key applied to the non-encrypted serial number for the power tool stored in the memory;
• generate the usage data based on data received from at least one sensor in the power tool during operation of the power tool;
• and
• transmit the usage data in association only with the first encrypted serial number to a maintenance system with the network device to enable usage data collection that prevents identification of the power tool as being associated with the usage data.