A data security apparatus includes an analog component. The analog component operates internally with a high degree of entropy. This high degree of entropy resides in the interactions between its internal components in response to an external driving signal. The interactions within the analog component have a level of entropy that is high enough to make digital simulation of the analog component impractical. Because the analog component is impractical to digitally simulate it is referred to as being digitally unclonable. The data security apparatus processes data by encrypting plaintext data into ciphertext and/or decrypting data from ciphertext into plaintext. Part of the conversion between plaintext and ciphertext uses the analog component. Since the analog component is digitally unclonable (that is, impractical to digitally simulate), the part of the conversion process that uses the analog component requires possession of the analog component itself or the possession of another analog component that has the same signature.