A system and method used for generating encryption keys on multiple devices and for encrypted data transfer between two or multiple devices. A sender system includes at least one sender device with nonlinear I-V characteristics. A receiver system includes at least one receiver device with nonlinear I-V characteristics. The at least one sender device with nonlinear I-V characteristics generates at least one sender output value used to create a string of characters or bits or bytes or numbers. The string of characters is used to encrypt data which is sent to the receiver device. The at least one receiver device with nonlinear I-V characteristics generates at least one receiver output value, and uses the at least one receiver output value to create the string of characters from the at least one receiver output value. A receiver processing unit generates the data from the encrypted data using the string of characters.