Cryptography System for Wireless Charging Modules

Applications

This technology employs a cryptography method that validates access keys in order to allow charging between wireless receivers and compliant chargers. The cryptography method follows a public authentication key protocol, where a receiver stores multiple public keys and a charger stores a single private key. If one of its public keys pairs with a charger’s private key, the receiver establishes a secure connection and begins the wireless power transfer process. A receiver also contains an envelope detector, which determines if the receiver is in proximity to the charger for successful power transfer.

Problem Addressed

Coupled inductors enable wireless recharging of personal electronics, wearable technologies, and IOT devices. Counterfeit wireless chargers that do not fulfil power specs of a device can send harsh transient signals, causing damage in the device’s battery and surrounding hardware. Secure hash algorithm (SHA) authentication protocols have been used to avoid charging problems between a charger-device pair. Unfortunately, these security protocols are not suitable for IOT systems, where a charger supplies power to multiple receivers.

Advantages

• Secure wireless power transfer
• Wirelessly charge multiple devices using one compliant charger