An intrusion-resistant apparatus may include a magnetic memory array disposed with an enclosure. The magnetic memory may include a plurality of magnetic memory elements, each adapted to store a binary value only in the presence of a predetermined bias magnetic field having a magnetic field strength and direction within predetermined limits. Means for providing the predetermined bias magnetic field and an encryption/decryption engine may be disposed within the enclosure. An encryption/decryption key may be stored in the magnetic memory array. The encryption/decryption key may be used by the encryption/decryption engine to encrypt and decrypt data.