Methods, systems, and devices for wireless communications are described. A first user equipment (UE) may generate a first encryption key and a second UE may generate a second encryption key based on a measurement of a channel between the first UE and the second UE. The second UE may transmit, to the first UE, a sidelink message including a one-way digital signature generated using the second encryption key and a message from a defined set of messages. The first UE may generate a set of one-digital signatures using the first encryption key and the defined set of messages and determine whether the one-way digital signature matches one of the set of one-way digital signatures. If there is a match, the first UE and the second UE may communicate using the encryption keys. Otherwise, the first UE and the second UE may generate new encryption keys.