US Patent 11606688 Secure key exchange mechanism in a wireless communication system

Security features for a wireless communications system including encryption and decryption of communications, secure key exchange, secure pairing, and secure re-pairing are provided. The encryption/decryption mechanism uses AES-256 block cypher with counter mode to generate blocks of cypher bits used to encrypt and decrypt communications between a master and devices. Session keys are generated using a random salt and a counter value. The random salt is generated using a secure random number generator. A master key (or device key) is also used in generating session keys. Impermanent session keys are used to encrypt/decrypt finite amount of data. Thereafter, the session key is replaced and cypher bits are generated using the new session key. A synchronized key jump procedure ensures that the master and device switch to the new session key at the same time.