Internet of Bio-Nano Things (IoBNT) is a domain where biochemical processes inside the human body communicate the cyber world of the internet. IoBNT paradigm stems from synthetic biology and nanotechnology tools and enables the engineering of biological embedded computing devices called nano-machines.
Nano-machines are powerful and functional man-made tiny devices. The functionality of these devices is inspired by the behavior of atomic and molecular structures composed of nanoscale components.
They not only function as computers but also establish connections with the environment (human body) to detect a physical quantity, as living organisms.
Communication inside the human body is as old as the existence of mankind. Indeed, the human body is a large-scale heterogeneous communication network of nano-networks as it is composed of billions of interacting nano-machines, i.e., cells, whose functionalities primarily depend on nanoscale molecular communications.
Hence, the vital conditions of the human body directly depend on the performance, reliability, and continuous functioning of intra-body molecular nano-networks.
Internet of Bio-Nano Things (Image Source: IEEE Communications Magazine)
IoBNT architecture is an extended version of the Internet of Things paradigm. IoBNT uses the cyber communication backbone of IoT. The main difference is in the perception layer, where the sensors are deployed. The sensors used in IoBNT are nano-scale and use the nano-scale communication technologies (Molecular Communication/ Terahertz based Nano electromagnetic Communication).
Following are the entities involved in IoBNT architecture:
Bio-Nano Things are biological computing machines that collect sensory data from the environment (inside the human body) and pass it to the bio cyber interface. Bio nano things are used interchangeably with nanomachines.
In order to develop efficient and novel nano-machines and to understand the communication mechanism between nano-machine, a study of biological cell architecture and their interactions has been proved helpful. Bio nano things are deployed in the form of nanonetworks inside the human body for biomedical applications. Below are five components of nanomachines.
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1. Control Unit: It contains the embedded software, which aims to perform the intended task of nanomachine. The control unit controls all the other components and could have a storage unit. The nucleus of a biological cell is responsible for realizing its intended tasks. Similar to software conditional expressions biological control unit encodes protein structures, data units, and regulatory sequences.
2.Communication Unit: The communication mechanism of nanomachine is realized through transceivers. Transceivers allow the embedded system to exchange information by transmitting and receiving messages at the nano level. The inter-cellular communication is realized through the gap junctions, hormonal and pheromonal receptors placed on the membrane of the cell.
3.Reproduction unit: It contains the instructions to fabricate the components of nano-machines and then to replicate them. This process takes place when nanomachines are replicated by saving the code of nanomachines in molecular sequences.
4.Power Unit: Power unit supplies stored energy to all the other components of nano-machines, to maintain the electrical current in embedded software. Mitochondrion, chloroplast, and Adenosien Triphosphate are some of the substances of cells that correspond to the external chemical reactions to produce energy. This chemical energy is stored in the cell reservoirs and supplied to regulate the other components of the cell.
5.Sensor and Actuators: This unit provides an interface between the environment and nanomachine. The sensing and actuation is the ability of a biological cell to distinguish external molecules or stimuli e-g chloroplast of plants and flagellum of bacteria.
Bio cyber Interface
Electronic tattoo can be used as bio cyber interface to communicate with in body biological nanonetwork(Image Source: IEEE Communications Magazine)
Biocyber interface is a specialized micro device that is usually implanted on the outer parts of the body. Bio cyber Interface acts as the transduction unit, which translates biochemical signals from the human body into electrical signals and electrical commands coming from healthcare providers into biochemical signals for in-body communication. Bio cyber interface has wireless communication capability which is used to communicate with gateway devices. The communication frequency of bio cyber interface is kept weak on purpose so that the high-frequency electromagnetic waves do not interfere with normal body functionality.
Image Source: Medical News Today
The gateway devices in IoBNT are usually a smartphone, tablets, PDAs or other wireless communication enabled handheld devices. Bio cyber interface communicates with gateway devices to send data and receive commands from the remote healthcare provider.
Internet access point
The connectivity mechanisms to forward and receive messages from healthcare provider/medical server. For example WiFi, 4G/5G, or other wireless communication mechanisms.
Photo by National Cancer Institue on Unsplash
It can be a cloud-based service for storing and processing health-related data of patients and a web portal used by healthcare providers to analyze reports and consign treatment
Nano-machines are only able to perform trivial tasks on their own; thus communication among nano-machines is very important to realize more complex tasks . Nano-machine communication technologies are divided into four groups namely:
Nanoscale Electromagnetic Communication
This type of communication is based on the transmission and reception of electromagnetic waves between novel nano materials such as carbon nanotubes and graphene based nanoribbons. The traditional transceiver of classical wireless communication is not feasible for nano-scale communication, however novel graphene based nano-materials have shown potential to overcome this limitation.Future electromagnetic nanonetworks are envisioned to operate on terahertz band, while few terahertz channel exist to date. Electromagnetic communication can make communication possible from micro device to nano device, and research is being made for the communication between nano devices or from nano to micro device.
Acoustic communication is realized by the transmission of ultrasonic waves through nano machine integrated transducers .These transducers should be capable to sense the variety of pressure and then react accordingly. Currently the size of transducers is the major barrier to implement this communication mechanism at nano-scale.
Nanoscale Mechanical Communication
In nano mechanical communication, the information is sent through nano machines that are linked physically. One of the major drawbacks for this communication technique in nano communication context is physical connection between devices. Therefore it is not workable for the applications where nano-machines have to be placed at distant locations.
Image source: IEEE Xplore
Molecular Communication (MC) is a molecule based communication paradigm that enables transmission of bio-chemical information (e.g. status of living organisms), which is not feasible using traditional communication. Molecules encoded with information to be transmitted, are called information molecules. The information molecules activate bio-chemical reaction at receiver and may recreate phenomena and/or chemical status, which sender then transmits. Molecular communication (MC) is considered the most promising nano networking mechanism due to its nano-sized transceivers that can easily integrate into nano machine. MC is bio-inspired and closely relates to the communication phenomena existent in nature for years.MC is also paramount choice for bio medical applications that involve intra body communication. Different schemes for molecular communication can be categorized into short range communication using calcium signaling, medium range signaling using molecular motors and long range signaling using pheromones.
Nano networking is a novelty in the IoBNT domain. Thus, here we focus on the security requirements in nanonetworking only. The cybersecurity for IoT has already been discussed extensively.
Global Security Goals
Global security goals for the classic communication paradigm are CIA (Confidentiality, Integrity, and Availability). These classic security goals will remain the same even in the context of the nano communication paradigm. For more holistic security requirements we have added ‘Authenticity’ as the fourth security requirement.
It is the most important issue in network security. This goal ensures that the context of the message exchanged between sender and receiver should not be accessible to an unauthorized entity. Encryption techniques can be used to add confidentiality to the communication.
It assures that the received information is complete and correct i.e., without being modified by an external entity. To ensure integrity in communication MAC (Message Authentication Code) hash functions can be used.
It assures that information is always available; the attacker should not be able to disrupt communication at any time. Setting redundancy to the network can assure availability.
It ensures that the source of message transmission is reliable and stops the attacker from sending fake messages.
Identification of attacks and threats is also important for network security. The attacks can be performed by two types of attackers; Internal attackers and External attackers.
Internal attackers are part of the system and have access to credentials and other information required to communicate with other system entities.
External attackers in the scenario of nano communication can be divided into two types: Local and remote attackers. Local attackers are located in the vicinity of attacked nanosystem. Attacks like eavesdropping and spoofing can be performed by these attackers. Remote attackers have to become local attackers before launching the attack.
The types of attacks launched by these attackers are classified into four groups:
Other types of attacks adopted from traditional networks are listed below:
Existing mechanisms of security and privacy used for traditional data communication networks cannot be applied directly to the nano communication network paradigm.
The existing cryptography and encryption techniques such as AES and RSA demand high computational power whereas nano-machines can only handle light-weight security solutions due to their nano-scale capacity. Using classical cryptography might be inefficient if only limited information is transmitted (like sending a small specific molecule to send one bit of information). Then adding a digital signature or long cryptography message authentication code is not appropriate. Many secure localization existing schemes are based on time-of-flight measurements; these are not directly applicable as they would require sub-nanosecond accuracy. However, there exist a number of bio-inspired algorithms for security that can be modified or down-scaled to the nanoscale level to make them feasible for nano-networks. Molecular Communication (MC) is one of the communication mechanisms of nano networking that uses molecules for information exchange. MC is itself bio-inspired and adapts the communication mechanisms existent in nature e-g communication inside the human body. There is an established research area that aims at using Bio-inspired approaches to solve problems according to the application domain. There are three research areas of bio-inspired approaches:
Bio-inspired computing represents a class of solutions that focus on providing efficient computing solutions e-g optimization algorithms and pattern recognition.
Bio-inspired systems class provides nature-inspired solutions for massively distributed and collaborative systems. Bio-inspired networking class provides strategies for efficient and scalable networking under uncertain conditions.
There exists a classification of bio-inspired approaches that provides efficient solutions for security to the computer networks.
The artificial immune system has been defined by Castro and Timmis as “adaptive systems, inspired by theoretical immunology and observed immune functions, principals and models, which are applied to problem-solving”. There are a number of appealing features that make an immune system, whether it is a natural or artificial suitable candidate for securing nano applications using molecular communication. Those features are robustness, reinforcement, memory, distributed, adaptive, recognition and dynamically changing coverage.
The main three research fields related to AIS are (1) Immune networks (2) Clonal Selection (3) Negative Selection.
The concept of the swarm is referred to a grouping of individual units to accomplish complex tasks that are difficult to be realized alone. Swarm based security approaches are highly potential for nano-networks security as they can be realized in lightweight systems. This type of security approach is highly effective since they are robust, self-configurable, and adaptive. The mechanisms adopted in nature to defend against attacks and intruders can be treated with swarm intelligence. Similarly, nanorobots have minimal intelligence and capabilities individually, but when they form a group, they can provide an effective mechanism against intruders.
Falko Dressler et al have defined biochemical cryptography as “a primitive that may be used for efficiently securing biologically based information channels.” The biochemical cryptography techniques proposed so far use DNA molecules for information encryption.
By connecting the human body to the outside cyber world through IoBNT poses a number of threats and security issues to the human body. There are a number of possible threats and attacks that can be launched to disrupt communication. Ian Akyildiz and his group members have coined the term "Bio Cyber terrorism" for IoBNT attacks in their pioneering work on IoBNT.Security mechanisms used for traditional networks demand high computation power which is beyond the capabilities of nano-machines. The available memory and processing capabilities of nano-machines are extremely limited, which makes use of complex communication algorithms and protocols impractical in nano regime. There is a huge asymmetry between the computational power of desktop computers and a single nano-machine. This limitation might affect the achievable security level, as one might have to work for short key lengths due to resource constraints which would allow attackers to easily perform brute-force attacks using high-performance computing e-g available through graphic cards. Bio-Inspired networking is an established research area that provides solutions, adapted from nature to a number of computing problems. IoBNT has many potential health applications which facilitate patients to relieve from lengthy medical tests, sparing time for appointments from health expert and necessity of being on the same location as that of health provider.
(Featured Image Source: IEEE Globecom)