The present invention provides a method for a data encryption device to perform network communications, the method comprising obtaining an indexed array of encryption keys, wherein the indexed array of encryption keys is shared with a data decryption device; obtaining a message to be encrypted; using a first random or pseudorandom number to determine an index; obtaining a first key from the array of encryption keys, wherein the first key corresponds to the index; selecting a second key from the plurality of encryption keys; encrypting the message using the first key and a second random or pseudorandom number; encrypting the index using the second key and a third random or pseudorandom number; transmitting the encrypted message and the encrypted index to the data decryption device.