Abstract: An example method is provided for resuming a communication session encrypted using a post-quantum cipher. The example method can include receiving, by a first computing system, a resumption message from a second computing system. The example method can include decrypting, by the first computing system, the resumption message to obtain a resumption secret, wherein the resumption secret is based on at least a portion of a shared secret that was obtained using a post-quantum cipher during a prior handshake sequence between the first computing system and the second computing system. The example method can include encrypting, by the first computing system, one or more messages using a session key based on the resumption secret. The example method can include sending, by the first computing system, the encrypted one or more messages to the second computing system.