US Patent 11695796 Device vulnerability detection during device handshake

Described are implementations that analyze the unencrypted messages of a cryptographic protocol handshake between two devices and/or the receipt or absence of encrypted messages of the handshake to detect security vulnerabilities of one or both of those devices. For example, the unencrypted messages of a TLS handshake between a client device and a server may be analyzed to determine security vulnerabilities of the client device. Because the disclosed implementations utilize the unencrypted messages of a handshake and/or detection of the receipt or absence of encrypted messages of the handshake, involvement in the handshake or decryption of encrypted messages of the handshake is not necessary. The requirement is that the disclosed implementations are able to observe the messages of a handshake that are used to establish a secure communication between the devices.