1.1 Wireless Power Consortium Terminology
The following terminology is provided to assist in understanding concepts related to the WPC Qi authentication standard as referenced in this application note. This section is intended to reflect the definitions used in the WPC standard; however, in all cases, the WPC standard takes precedence over the descriptions provided here.
- Power Receiver
- The device that is charged by the power transmitter and communicates with the transmitter for authentication purposes or to control the charging process.
- Power Transmitter
- The device that provides power to, and communicates with, the power receiver. The secure storage subsystem resides within the power transmitter.
- Qi
- The designation used by the WPC for standards related to wireless charging of mobile devices.
- Revocation Sequential Identifier (RSID)
- A unique identifier stored in the WPC device unit certificate that uniquely identifies a power transmitter. The RSID may be used to revoke high-power operation or completely disable a transmitter for noncompliance reasons.
- Secure Storage Subsystem (SSS)
- The device used to securely store the security credentials required to authenticate a wireless power transmitter. This may be implemented as a secure element or secure crypto device.
- Wireless Power Consortium (WPC)
- The standards body responsible for defining all aspects of wireless charging associated with the Qi standards, as well as licensing and certifying Qi-certified products. Membership in the WPC is required to produce Qi-compliant power transmitters or receivers. Additional information is available at: www.wirelesspowerconsortium.com/.
- WPC Manufacturer
- A company or entity licensed by the WPC to manufacture certified WPC power transmitters. All WPC manufacturers must execute a WPC manufacturer agreement.
- WPC Manufacturing CA
- A company licensed by the WPC to manufacture secure storage subsystems for use in certified WPC power transmitters. Microchip is an example of a licensed manufacturing CA.
- WPC Root Authority
- The top-level within the WPC certificate hierarchy. All WPC manufacturing certificates are issued and signed by the WPC Root Authority.
- WPC Slot
- As defined in the WPC authentication specification, a slot is a storage element that contains a WPC certificate chain. Four slots (Slots 0-3) are defined. Slot 0 is mandatory and must contain a WPC certificate chain. Slot 1, if used, is also reserved for a WPC certificate chain. Slots 2 and 3 are undefined and reserved for optional proprietary extensions.
- WPC Slot Digest
- A 32-byte cryptographic digest representing the complete chain stored within a WPC Slot. This digest may be retained by the host system to optimize and accelerate the authentication process.