Zero-Power Defense Done Right: Shielding IMDs from Battery-Depletion Attacks

Abstract

The wireless capabilities of modern Implantable Medical Devices (IMDs) make them vulnerable to security attacks. One prominent attack, which has disastrous consequences for the patient's wellbeing, is the battery Denial-of-Service attack whereby the IMD is occupied with continuous authentication requests from an adversary with the aim of depleting its battery. Zero-Power Defense (ZPD), based on energy harvesting, is known to be an excellent protection against these attacks. This paper raises essential design considerations for employing ZPD techniques in commercial IMDs, offers a critical review of ZPD techniques found in literature and, subsequently, gives crucial recommendations for developing comprehensive ZPD solutions. Keywords Implantable medical device • IMD • Energy harvesting • Wireless power transfer • Zero-power defense • Authentication protocol • Denial-of-service attack • Battery DoS • Battery-depletion attack This work is an extended version of [49], which was presented at the 16th ACM International Conference on Computing Frontiers. This paper improves the original article by (1) introducing additional design considerations in Section 4, (2) adding nonharvestingbased-ZPD works in Section 5, (3) discussing the impact of electromagnetic-noise attacks on IMDs in Section 6.2, and (4) proposing the novel concept of a standalone ZPD module along with the taxonomy of ZPD implementations in Section 6.

Securing Implantable Medical Devices Using Ultrasound Waves

“…As a result, for an EH-ZPD design, a different band should be used for energy harvesting. This requires a separate antenna, and hence, results in the increased cost and size [7]. This can be overcome by using a 13.56 MHz ISM band for both the data communication and WPT.…”

“…SecureEcho allows the use of a bedside base-station reader after its initial BCC pairing with the IMD. On the other hand, in the case of EH-ZPD, harvesting RF energy over the bedside range (a few feet) requires larger antennas/coils, and longer delays due to the charging of the energy reservoir, which complicates the IMD design [7].…”

“…E sec includes the energy consumed by the security computations, data handling and the RF transceiver. E med includes the energy consumed by the medical application, the sensing of physiological signals, and the electrical stimulation applied on the human tissue [7].…”

“…In the case of SecureEcho, E sec is shown in (7). Here, P M CU is the average active-mode power consumption of the security MCU.…”

“…We will use the term energy harvesting for both RF-and inductivecoupling-based harvesting techniques available in literature[7].VOLUME 4, 2016 …”