Smart Home Activity Log Privacy via Hashing and Encryption

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Smart home systems with centralized management devices face privacy concerns due to unified activity logging, as server devices can access potentially sensitive information from individual smart home devices.

Innovation Solution

Implementing a method that includes hashing activity tags and encrypting activity information at a centralized management hub, ensuring that server devices cannot discern the underlying content of activity logs by using hash functions and encryption keys accessible only to the hub.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If centralized management hub unifies activity logging from multiple smart home devices, then system management efficiency is improved, but user privacy is compromised due to server access to sensitive information

Engineering Contradiction:

Improvesystem management efficiencyVSAvoiduser privacy exposure

Core Design Contradiction:

ProductivityVSObject-affected harmful factors

Solution Approach 1:

The patent extracts sensitive information (activity tags and activity information) from the activity log data before storing it on the server. By removing the harmful element (sensitive content) while retaining the useful structure (log entries with timestamps and hashed identifiers), the system achieves both centralized management efficiency and privacy protection.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The centralized management hub acts as an intermediary between smart home devices and the server. It processes activity logs by hashing sensitive tags and encrypting activity information, transforming the data into a form that can be stored centrally without exposing private information to the server.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Object-affected harmful factors

If activity logs are encrypted and hashed at the centralized management hub, then user privacy is protected, but data retrieval complexity increases

Engineering Contradiction:

Improveuser privacy protectionVSAvoiddata retrieval complexity

Core Design Contradiction:

Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The system performs preliminary hashing of activity tags and encryption of activity information at the time of log creation, rather than at retrieval time. This preliminary processing stores the transformed data in a structured format that enables efficient retrieval through the centralized management hub, which maintains the decryption keys and hash mappings.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The centralized management hub maintains self-service capabilities by storing the hash functions and encryption keys locally. When retrieval is needed, the hub automatically performs the reverse operations (decrypting and unhashing) without requiring external intervention, thus managing the complexity internally while providing simple interfaces to users.

Inventive Principle:

Principle #25Self-service

3Object-affected harmful factors

If server devices cannot access sensitive information in activity logs, then user privacy is maintained, but system debugging and monitoring capabilities are reduced

Engineering Contradiction:

Improveuser privacy maintenanceVSAvoidsystem debugging difficulty

Core Design Contradiction:

Object-affected harmful factorsVSDifficulty of detecting and measuring

Solution Approach 1:

The patent applies different quality treatments to different parts of the activity log data. Sensitive fields (activity tags and activity information) are hashed and encrypted, while non-sensitive fields (timestamps and device identifiers) remain in plain text. This selective processing allows the server to monitor and debug using non-sensitive data while privacy is protected for sensitive information.

Inventive Principle:

Principle #3Local quality

Data Source

PatentUS12579306B2Techniques for managing activity logs in a manner that promotes user privacy

Publication Date: 2026.03.17 APPLE INC

AI summary

Disclosed herein are techniques for managing activity logs in a manner that promotes user privacy. One technique can by implemented by a centralized management hub, and include the steps of (1) receiving, from a peripheral device, information about activity detected by the peripheral device, where the information includes at least one activity tag, (2) identifying a hash function, (3) providing the at least one activity tag to the hash function to generate at least one hash value, (4) encrypting, using an encryption key that is accessible to the centralized management hub, at least a subset of the information to produce encrypted information, and (5) causing a server device to store, in an activity log associated with the centralized management hub, an activity log entry that includes: a timestamp corresponding to a time at which the activity log entry is stored, the at least one hash value, and the encrypted information.