An example client device includes a processor configured construct a key to be used to encrypt or decrypt data of a communication session between the client device and a server device, partition the key into a plurality of key partitions, send data representative of the key and a location of the client device to the server device, send data representative of each of the plurality of key partitions to a respective key verification server device of a plurality of key verification server devices, and after receiving an indication from the server device that the key has been verified using data representative of the key, the location of the client device, and the plurality of key partitions, encrypt or decrypt data exchanged with the server device using the key.