Abstract: An encryption key, required to encrypt and decrypt data according to a predefined algorithm is usually retained in a volatile memory device. Detection of loss of the key or corruption of the key is frequently possible only be means of the encryption circuit itself testing the key. Automated and repetitive testing of encryption keys by means of a processor or a control circuit periodically requesting the encryption circuit to test an encryption key minimizes data loss and system down time due to corrupted or lost keys.

Abstract: Ceramic dielectric substrates, calcium titanate, bismuth titanate and strontium titanate, used with superconductor, Ytrium Barium Copper Oxide, or YBC, as an electrode, produce a superconducting electrical device, useable as a filter or capacitor. The electrical device formed by using one of the dielectrics taught herein in combination with YBC, is mechanically stable in comparison to prior art ceramic dielectrics that used YBC for an electrode material, in that the YBC is substantially free of microcracks and remains bonded to the substrates.