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Citation: Tahir, S.; Tahir, H.; Tahir, R.;
Rajarajan, M.; Abbas, H. Water Is a
Viable Data Storage Medium:
A Security and Privacy Viewpoint.
Electronics 2022,11, 818. https://
doi.org/10.3390/electronics11050818
Academic Editor: Dimitra I.
Kaklamani
Received: 12 January 2022
Accepted: 3 March 2022
Published: 5 March 2022
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electronics
Article
Water Is a Viable Data Storage Medium: A Security and
Privacy Viewpoint
Shahzaib Tahir 1,*,† , Hasan Tahir 2,† , Ruhma Tahir 3,†, Muttukrishnan Rajarajan 4,*,† and Haider Abbas 1,†
1Department of Information Security, College of Signals, National University of Sciences and Technology
(NUST), Islamabad 44000, Pakistan; dr.h.abbas@ieee.org
2Department of Computing, School of Electrical Engineering and Computer Science, National University of
Sciences and Technology (NUST), Islamabad 44000, Pakistan; hasan.tahir@seecs.edu.pk
3School of Computer Science and Electronics Engineering, University of Essex, Colchester CO3 3SQ, UK;
rtahir@essex.ac.uk
4School of Mathematics, Computer Science and Engineering, University of London, London EC1V 0HB, UK
*Correspondence: shahzaib.tahir@mcs.edu.pk (S.T.); r.muttukrishnan@city.ac.uk (M.R.)
† These authors contributed equally to this work.
Abstract:
The security of IoT devices is a major concern that needs to be addressed for their wide
adoption. Users are constantly seeking devices that are faster and capable of holding large amounts
of data securely. It is purported that water has memory of its own and the ability to retain memory of
the substances that are dissolved into it, even after being substantially and serially diluted. It was
also observed in the lab setting that the microscopic pattern of water obtained from the same vessel
by different people is unique but can easily distinguish those individuals if the same experiment is
executed repeatedly. Furthermore, extensive research is already underway that explores the storage of
data on water and liquids. This leads to the requirement of taking the security and privacy concerns
related to the storage of data on water into consideration, especially when the real-time collection of
data related to water through the IoT devices is of interest. Otherwise, the water memory aspect may
lead to leakage of the data and, consequently, the data owners identity. Therefore, this article for the
first time highlights the security and privacy implications related to water memory and discusses the
possible countermeasures to effectively handle these potential threats. This article also presents a
framework to securely store sensitive data on water. The proof-of-concept prototype is implemented
and tested over a real-world dataset to analyze the feasibility of the proposed framework. The
performance analysis yields that the proposed framework can be deployed once data storage on
water is widely used.
Keywords: water memory; security; privacy; distinguishability; searchable encryption; DNA
1. Introduction
Today’s world has become a global village where people rely on automation and
technology to perform routine tasks. Although the reliance on technology has numerous
benefits, including on-demand availability of resources and data, the existing data storage
devices cannot cope with the data storage needs that are exponentially increasing. Fur-
thermore, it is estimated that the world’s data will hit 175 zettabytes by 2025 [
1
,
2
]. Smart
devices are generating colossal amounts of data, which are processed and analyzed to make
smarter decisions, provide necessary support and optimize functionalities.
The internet of things (IoT) is a technological revolution incorporating the latest
technologies in both hardware and software. The IoT has already had a noteworthy impact
on multiple societal verticals, such as healthcare [
3
], smart cities [
4
], manufacturing [
5
],
home automation [
6
], communications [
7
], agriculture [
8
], etc. The IoT owes its success
primarily to innovations in the field of communications and sensing technologies. The
IoT ecosystem is positioned to make an even stronger impact as innovators and device
Electronics 2022,11, 818. https://doi.org/10.3390/electronics11050818 https://www.mdpi.com/journal/electronics
Electronics 2022,11, 818 2 of 15
manufacturers conceive new designs and application areas. The world is constantly looking
for IoT devices that are smarter, incorporate a wider range of functionality, possess higher
resources and are able to inter-operate with one another. While all these factors are very
much needed, little emphasis is placed on security and privacy concerns associated with
IoT devices. To place IoT devices in every home and office, designers will need to provide
security as a fundamental design element. Adversaries are able to take advantage of
limited or poor security implementation, thus compromising the security and privacy
of individuals [
9
]. Owing to their pervasive nature, IoT devices store and process large
quantities of data. Data are frequently stored, using conventional magnetic storage of
semiconductor-based chip storage. Sophisticated technologies are now equally accessible
to adversaries, which makes it possible for them to capture device data and communications.
To thwart attacks against storage mediums, a novel form of data storage is needed. This
leads to a compelling case to have alternate methods of data storage that is able to meet
growing demands for data storage with the provision of security. To overcome this problem,
the use of liquid and water deoxyribonucleic acid (DNA) to store data has been studied [
10
].
It is purported that water has the ability to retain memory of the antibodies that come
in contact with it, and thus the term “Water Memory” or “Memory of Water” evolved [
11
].
The study of homeopathy [
12
] and magnetized water is also based on the belief that water
changes its molecular structure, with its ability to remember interactions, and retains this
new structure in the future when exposed to external substances, materials or objects.
While storing data on liquid or water, an attacker can exploit the property of water memory,
leading to security and privacy concerns. Data security in this context means limiting
unauthorized access to the data stored on the water, thus dealing with data confidentiality.
Privacy refers to safeguarding the user identity or the identity of the individual who
has come in contact with water. By default, the security and privacy concerns remain
unexplored in the literature.
Contributions
The following contributions are made through this research:
•
This article for the first time sheds light on the potential security and privacy risks
associated with data storage on the DNA of liquid and water. The importance of this
study stems from the fact that if the concerns remain unaddressed, they could lead to
data misuse and data theft.
•
The countermeasures are also proposed in this article to effectively mitigate the possi-
bility of attacks. A framework is presented to securely store sensitive data on water
and presents strategies to counter the security and privacy risks.
•
A proof-of-concept prototype is implemented and tested over a real-world dataset
to analyze the performance of the proposed framework. The performance results
demonstrate the efficiency of the proposed framework, and hence, it can be used in a
real-world environment.
The paper is organized as follows: Section 2highlights the water memory beliefs by
explaining the concept of water memory. It also cites the articles in favor of and against
the concept of water memory. Section 3for the first time explains the security and privacy
implications associated with data storage on water and water memory. Section 4presents
a novel framework for achieving data security and privacy. Section 5presents the proof-
of-concept prototype and highlights the complexity of the system by testing it over a
real-world dataset. The conclusion and future work are drawn toward the end in Section 6.
2. Water Memory Beliefs
Before exploring the evidence of water memory, it is important to define the term
“water” in this context. Then we discuss the research studies that are in favor of this
concept, followed by the studies that are against the evidence of water memory. This
article is primarily based on the proposition of water having memory and brings to light
many concerns.
Electronics 2022,11, 818 3 of 15
2.1. Water in the Context of “Water Memory”
Water is a mineral solvent and has the capacity to dissolve numerous fluids and
substances. Real, pure water, free from all foreign molecular species, cannot be produced.
This also holds true for distilled and deionized water. Pure water is generally known as
neutral water, i.e., pure water has a pH value of exactly 7 (where a pH value between 0
and 7 means the water is acidic; a pH value between 7 and 14 describes alkaline water).
Therefore, water is considered to be a very complex structure, especially when used in
the context of water memory and data storage on water. Water in the context of water
memory is assumed to be a solution of various, varying materials and substances that are
dissolved/suspended in the water [
13
]. The water used in the experiment presented in the
next section is tap water.
2.2. Evidence in Favor of “Water Memory”
This section discusses the experiments that were conducted to demonstrate the ability
of water to store information. This discussion lays the foundation and will help us highlight
the security and privacy concerns that are introduced by storing data on water.
2.2.1. Water Exposed to Individuals
Kröplin and Henschel in [
14
,
15
] analyzed water droplets under a darkfield microscope
with the intention to identify whether water samples can distinguish between the people
carrying out the experiment. Figure 1demonstrates the experiment and the outcome. The
experiment was performed between four participants. The experiment is conducted in
the same room, and the participants are placed 1.5 m apart to avoid interactions. Every
individual uses a one-way syringe to place 4 small drops of tap water on the microscope
slide. Once the slides have dried, they are photographed using a dark field microscope and a
camera, where the dark field microscope is set to magnification factor 40. The experimental
results illustrate how each row corresponds to the experiment carried out by a particular
individual. A pattern can be observed within a single sample (row). However, intra-sample
(columns) patterns are not similar. Therefore, under this experiment, water has the ability
to store individual specific information.
Version February 25, 2022 submitted to Journal Not Specified 3 of 16
2.1. Water in the context of “Water Memory" 85
Water is a mineral solvent and has the capacity to dissolve numerous fluids and
86
substances. Real pure water, free from all foreign molecular species cannot be produced.
87
This also holds true for distilled and deionized water. So pure water is generally known
88
as neutral water i.e., the pure water has a pH value exactly 7 (where a pH value between
89
0 and 7 means water is acidic; pH value between 7 and 14 is described as alkaline water).
90
Therefore, water is considered to be a very complex structure especially when used in the
91
context of water memory and data storage on water. Water in the context of water memory
92
is assumed to be a solution of various, varying materials and substances that are dissolved/
93
suspended in the water [
6
]. The water used in the experiment presented in the next section
94
is tap water. 95
2.2. Evidence in favour of “Water Memory" 96
This section discusses the experiments that have been conducted to demonstrate the
97
ability of water to store information. This discussion lays the foundation and will help us
98
highlight the security and privacy concerns that are introduced by storing data on water.
Figure 1. Experiment- Waterdrops on a microscope slide, individuals and water memory.
99
2.2.1. Water exposed to individuals 100
Kröplin and Henschel in [
7
,
8
] analyze water droplets under a darkfield microscope
101
with the intention to identify whether water samples can distinguish between the persons
102
carrying out the experiment. Figure 1demonstrates the experiment and the outcome.
103
The experiment is performed between 4 participants. The experiment is conducted in the
104
same room and the participants are placed 1.5 meters apart to avoid interactions. Every
105
individual uses a one way syringe to place 4 small drops of tap water on the microscope
106
slide. Once the slides have dried, they are photographed using a dark field microscope
107
and a camera, where the dark field microscope is set to magnification factor 40. The
108
experimental results illustrate each row corresponds to the experiment carried out by a
109
particular individual. A pattern can be observed within a single sample (row). Although
110
Figure 1. Experiment—water drops on a microscope slide, individuals and water memory.
Electronics 2022,11, 818 4 of 15
2.2.2. Water Exposed to “Things”
This experiment was conducted by Masaru Emoto [
16
]. The researcher, through
several experiments, demonstrated that water, when exposed to different things, such as
music, written words, visual images and photographs, has the ability to absorb, hold and
re-transmit human feelings. The author took a drop of water and froze it at
−
20
°
C, then
analyzed the crystal structure under a microscope. The experimental results are indeed
spectacular (as shown in the Figure 2). It was observed that water is a sensitive medium
and the crystal structure is affected when water is exposed to harsh words, specific and
concentrated thoughts, such as “I will kill you” and “You fool”, or heavy metal music. The
pattern is mainly dull and asymmetric in the case of negative exposure. Similarly, if loving
words, light music or beautiful pictures are directed toward water, the crystal structure
shows a colorful, symmetric snowflake pattern. This experiment clearly indicates that
water has the ability to store and re-transmit human feelings.
Version February 25, 2022 submitted to Journal Not Specified 4 of 16
intra-sample (columns) patterns are not similar. Therefore, under this experiment, water
111
has the ability to store individual specific information. 112
2.2.2. Water exposed to “things" 113
This experiment was conducted by Masaru Emoto [
9
]. The researcher, through several
114
experiments demonstrates water when exposed to different things such as music, written
115
words, visual images and photographs, has the ability to absorb, hold and retransmit
116
human feelings. The author takes a drop of water and freezes it at -20°C and analyzes
117
the crystal structure under a microscope. The experimental results are indeed spectacular
118
(as shown in the figure 2). It is observed that water is a sensitive medium and the crystal
119
structure is effected when water is exposed to harsh words, specific and concentrated
120
thoughts such as "I will kill you", "You fool" or heavy metal music. The pattern is mainly
121
dull and asymmetric in-case of negative exposure. Similarly, if loving words, light music
122
or beautiful pictures are directed towards water, the crystal structure shows a colourful,
123
symmetric snowflake pattern. This experiment clearly indicates that water has the ability
124
to store and re-transmit human feelings. 125
Figure 2. Experiment-Hidden Messages
2.3. Counter-evidence for “Water Memory" 126
Although the concept of water memory sounds interesting and ground-breaking, it
127
gave rise to many controversies and the idea was not widely accepted by researchers.
128
The reason behind this idea failing to convince the community was that it was thought
129
that the experiment was against our knowledge on the physics of water and other teams
130
failed to reproduce the same experiment. Readers are referred to [
10
] to have an insight
131
on the counter evidences. The same paper [
10
] gives a new direction to the controversy
132
and explains why the experiments could not reproduce the results; “that the outcomes of
133
these experiments were related to quantum-like interference of the cognitive states of the
134
experimenter". Therefore, quantum-like probabilistic model would allow to describe how
135
the experiments were carried out. 136
As we begin to use water as a data storage medium , it is necessary to give importance
137
to even the least possibility of water memory as it could cause severe security and privacy
138
leakages. Therefore, we consider the aspect where data has the ability to retain memory. 139
Figure 2. Experiment—hidden messages.
2.3. Counter-Evidence for “Water Memory”
Although the concept of water memory sounds interesting and groundbreaking, it
gave rise to much controversy, and the idea was not widely accepted by researchers. The
reason behind this idea failing to convince the community was that it was thought that
the experiment was against our knowledge on the physics of water, and other teams
failed to reproduce the same experiment. Readers are referred to [
17
] for insight on the
counter evidences. The same paper [
17
] gave a new direction as to the controversy and
explained why the experiments could not reproduce the results: “that the outcomes of
these experiments were related to quantum-like interference of the cognitive states of the
experimenter”. Therefore, a quantum-like probabilistic model would allow to describe how
the experiments were carried out.
As we begin to use water as a data storage medium, it is necessary to give importance
to even the least possibility of water memory, as it could cause severe security and privacy
leakages. Therefore, we consider the aspect where data has the ability to retain memory.
2.4. Water and Liquid as a Data Storage Media
It is believed that the liquid hard drive will have the ability to store a terabyte of data
in a tablespoon full of liquid [
18
]. In fact, when liquid and water are examined minutely,
there are microscopic particles suspended within them. These microscopic particles can
replicate a solid hard drive’s platters by encoding the data in binary and storing it on the
DNA strands. DNA computing offers the following advantages [19]:
•Increased performance rate
allows 1026 simultaneous operations per second, en-
abling the performance of the data storage on the DNA strands to increase at an
exponential rate.
Electronics 2022,11, 818 5 of 15
•Low power consumption
, as the increased performance rate allows to operate 10,000
times the speed of today’s supercomputers while consuming fewer resources.
•Incredibly lightweight due to efficient and lightweight biochemical operations.
•Increased data capacity
as the DNA has the ability to store 2.2 exabytes per gram, i.e.,
a single cubic centimeter of DNA holds more information than a trillion CDs.
•Imperishable storage
as DNA strands have the ability to retain data and remain in a
stable state under controlled conditions.
Although data DNA computing and data storage on DNA have many advantages,
the security and privacy concerns are yet to be explored in relation to water memory. The
meaning of security and privacy in the context of water memory is already discussed in
Section 1.
3. Data Security and Privacy Implications
This section focuses on the security and privacy implications related to data storage
on water. Figure 3highlights the hierarchy of controls deployed to achieve data security
and privacy within an organization. Considering data storage on water, the objectives
and controls are broadly categorized into a low level and high level. Low-level areas refer
to possible threats whose mitigation strategy may require the modification/tuning of the
organization’s architecture at the system level. This would help to integrate data storage
on water, and achieve data security and privacy. High-level areas are generally those that
add value to the security and privacy mechanisms that were put in place at the policy
and governance level (low level). Table 1extends these areas and highlights the possible
concerns while storing data on water/liquid and presents some recommendations. The
below discussion extends the recommendations further by exploring the strategies that can
be adopted to achieve security and privacy, and to contain the risks.
Figure 3. Information security controls.
Electronics 2022,11, 818 6 of 15
Table 1. Possible security and privacy concerns while storing data on water.
Areas Recommendations
Low Level
Data Protection • Ensure appropriate methods exist for the protection of data at rest, motion and in use.
• Provision methods for data sanitization.
Identity and Access
Management
•
Ensure security mechanisms for authentication, authorization, access control are imple-
mented and adequate for the business processes and systems.
Compliance •
Understand the laws and regulations applicable, mainly related to data, its security and
privacy such as GDPR and HIPAA.
•
In case an organization is providing water-based data storage-as-a-service be aware of the
contract terms mentioned in the service level agreements (SLA)
High Level
Governance • Have Standardized policies and procedures
• Distribute Management
• Define clear roles and responsibilities
• Put audit mechanisms in place
Trust • Deliver confidence to stakeholders by permitting security and privacy controls.
•
Create a monitoring method that supports decision making, performance monitoring,
compliance, value delivery.
• Establish a risk management protocol that is adaptive to changing risk landscape.
Architecture • Establish an understanding of the system and implemented security controls.
• Determine the impact of the security controls on the system end to end.
Availability •
Ensure business continuity in the event of loss through availability, backup, data and
disaster recovery.
Data Lock-in •
Create methods that reduce data lock-in and promote platform sharing and data portability
by limiting vendor specific behavior.
3.1. Low-Level Areas
3.1.1. Data Protection
Data protection refers to implementing security controls for the protection of data
owners and data consumers. Ultimately, the level of data protection is dictated by the
organization or the standards with which it complies. To be effective, data protection
has to be provided by the design. This means the protection by default privacy must be
ensured and that it is proactive in nature. The data protection mechanisms should be fully
functional and service provision should be end-to-end, while respecting user privacy at the
same time. Modern data protection laws also dictate the need for placing privacy controls
in the hands of the data owners and not the data consumers. The data protection can be
widely achieved through deploying cryptographic mechanisms.
3.1.2. Identity and Access Management
Identity and access management relates to the mechanisms that entail identity proofing
and authentication mechanisms. These mechanisms in place allow only an authorized
person to access sensitive data stored on a storage medium. As discussed in Section 2,
water has its own memory; therefore, it is essential that only an authorized person should
be able to access the water and the data stored on it. While storing sensitive data on
water, it is very important to have identity and access management in place that governs
the user provisioning, maintenance and protection of the sensitive data outsourced to an
organization. The traditional data structure, such as access control lists and access control
matrix, are able to conform to water-based data storage.
Electronics 2022,11, 818 7 of 15
3.1.3. Compliance
Before an organization shifts toward storing data on water, it is important to be
aware of regulations that apply to the target sector. For example, an organization may
require regulation compliance that includes GDPR, FISMA, HIPAA, NIS Directive, etc. For
organizations interested in using water as a data storage medium, regulation compliance
is crucial, as the organizations may be handling sensitive and private data. For such
organizations to be compliant, the understanding of standards helps achieve the regulatory
compliance. The standards mainly belong to the family of ISO-27000 that helps manage
the security of the assets, or PCI-SSC that standardizes the payment card industry. To
fully benefit from data storage on water, an organization should understand the domain-
specific regulations and tune/design a water-based data storage system such that the
regulatory requirements are met. This would help an organization to effectively manage
the compliance risk and with the compliance auditing. The regulatory compliance is also
reflected in the service level agreements and contracts between the client, and the client
may consider himself/herself to be protected against data leakage and data theft.
3.2. High-Level Areas
3.2.1. Governance
Governance in terms of security refers to having a set of tools, personnel and business
processes in place that achieve the security goals for meeting the organization’s needs.
Information security governance also defines an organization’s structure, roles and re-
sponsibilities, performance measurement, defined tasks and oversight mechanisms. An
organization planning to use water as a data storage medium must focus on governance,
as it adds another layer of accountability for attaining transparency and traceability. The
predefined policies, standards and procedures help mitigate the risks and help achieve
confidentiality, integrity and availability. Such an organization may rely on frameworks,
such as ISO 38500, balanced scorecard, COBIT, systems security engineering capability
maturity model (SSE-CMM), etc. [20].
3.2.2. Trust
To fully benefit from the services that an organization has to offer requires the cus-
tomers to have full trust of the organization. Trust is generally subjective in nature and
depends upon the type and sensitivity of the data that a user is willing to store. If an
organization is planning to provide data storage as a service on water, they would need
to have trust mechanisms and service level agreements in place. Although outsourcing
has many benefits, it gives rise to the risk associated with insider access and debatable
data ownership, which could lead to loss of data control and eventually reduced trust.
Cryptographic mechanisms may be deployed to achieve security and privacy. Additionally,
threat-monitoring and risk-management protocols should be deployed to effectively reduce
the potential threats.
3.2.3. Architecture
It is believed that prevention is better than cure. For an organization willing to use
water as a data storage medium, it is important to understand the architecture. This mainly
refers to the architecture of the software and hardware used to deliver the services of
data storage on water to the clients. The architecture is very important, as the clients
are generally located at different geographic locations and rely on virtual machines or
hypervisors to access the remote resources. By introducing a remote location for data
storage, the attack surface may be extended. Thus, a clear understanding of the architecture
is required, and controls, such as virtual firewalls, intrusion detection and prevention
systems, may be deployed.
Electronics 2022,11, 818 8 of 15
3.2.4. Availability
As water-based storage is considered a space-efficient data storage method, enterprises
will be willing to use it as a suitable method for off-site and on-site backup. The offering of
availability through water-based storage requires that in the event of a disaster, enterprises
are able to restore functionality and switch between primary and backup sites with minimal
downtime. Other requirements when considering water-based backup is the cost efficiency
compared to the benefits brought to the business. The ability to perform an automated
switchover and ensuring high system performance post switching is also mandatory.
3.2.5. Data Lock-In
Data lock-in [
21
] refers to the inability of being able to move/migrate data between
different storage data structures and the cloud. The movement of data from one storage
to another is a necessary requirement when one is switching vendors, performing data
backup or is involved in any migration-related activity. The inability to to move data means
that users are locked into the current data storage method and cannot migrate to and from
water-based storage. The prevention of lock-in will require services and APIs that assist in
the process of migration. Additionally, proprietary data types and data structures need to
be avoided since they are not readily understood by other vendors. This brings to light the
need for the standardization of water-based storage data structures.
4. Proposed Framework to Achieve Security and Privacy over Sensitive Data Stored
on Water
With the help of a scenario, a framework is presented to explain one of the possible
routes that may be taken to outsource sensitive data to an organization that uses water-
based data storage. This framework concentrates on low-level threats (discussed in the
previous section) and presents mitigation strategies. Suppose Bob outsources his sensitive
data but he does not trust the data storage service provider. Direct (unencrypted) data
storage on water can lead to unauthorized data access and misuse of the data. The general
data protection regulations (GDPR) also insist that people should have full control over
their data. Therefore, to achieve data protection, avoid data misuse and comply with the
GDPR requirements, a method is to encrypt and then store the data on the DNA strands.
Figure 4presents a holistic view of the flow of events that would take place to store the
encrypted data on a drop of water or liquid. Firstly, all the data that need to be stored on
the water medium are encrypted, and the corresponding hexadecimal values are obtained.
The hexadecimal values are converted to binary. The binary values are represented as
a sequence of nucleotide bases (As, Ts, Cs, and Gs) and stored as DNA strands that are
contained in molecules of water or any other liquid. Later on, the DNA strands may be
accessed to retrieve the data stored on it. DNA cryptography is a mathematical and a
systematic approach that achieves storage of encrypted data on a DNA sequence.
Electronics 2022,11, 818 9 of 15
Figure 4. Encrypted data storage on a drop of water/liquid.
4.1. DNA Cryptography
Cryptography is a technique that performs mathematical operations on the data
aimed to achieve information security, such as data confidentiality, data integrity and
non-repudiation. DNA cryptography is the technique of hiding the data that are stored in
DNA strands and sequences. In simpler terms, DNA cryptography relies on the conversion
of each alphabet into a different combination of four bases. This is an active area of
research, and over the years, different methods to achieve DNA cryptography have been
proposed [22,23].
The storage of encrypted data on DNA strands seems to be a feasible solution but
gives rise the problem of searching and sifting through the large amounts of encrypted
data stored in the DNA sequences. To handle this significant problem, a naive approach
would be to decrypt the data and then search over it. However, this approach results in
an increase in the computation overhead. Therefore, a mechanism is required that allows
on-the-fly searching over the encrypted data. Therefore, searchable encryption is proposed.
4.2. Searchable Encryption on DNA Strands
Searchable encryption [
24
,
25
] is a technique widely being explored in the area of cloud
computing, where large amounts of data are stored in the cloud. Searchable encryption
allows a user to generate a search query (also called a trapdoor) and can delegate the
search across the peers involved in a network. A searchable encryption schemes offers the
following properties:
•
Only an authorized person is allowed to generate a meaningful trapdoor/search query
that can be used to perform the search.
•Only an authorized person is able to decrypt the data.
Searchable encryption over a DNA sequence [
26
] is an emerging area of research,
and very little research has been conducted to address this problem. In the context of
data storage on DNA strands and water, searchable encryption can be used to achieve
confidentiality of the data [
27
]. Searchable encryption will limit the possibility of data theft
and data misuse. Furthermore, modern searchable encryption schemes also preserve the
privacy of the data owner and the user performing the search by generating probabilistic
trapdoors. A probabilistic trapdoor is a unique search query generated for the same
keyword searched repeatedly. Therefore, an attacker maintaining a history of the past
Electronics 2022,11, 818 10 of 15
searches cannot uncover the underlying text or the keywords that have been searched. A
comparison of different searchable encryption techniques is presented in [28].
4.3. Authentication, Authorization and Access Control
DNA cryptography and searchable encryption primarily achieve confidentiality of the
data; however, the interaction of a user with water and water memory itself can lead to
serious privacy concerns that need to be addressed separately. Only authenticated entities
should be able to access the data. This also ensures non-repudiation and accountability
based on secure credentials associated with the individuals. There are several methods
to achieve privacy of the data source to restrict unauthorized access to the water/liquid.
This framework proposes to integrate technologies specifically designed for enforcing
authentication and access control. The framework utilizes the services of an application
encryption (AE) server [
29
] to govern all the access control policies that would be involved
in the framework. The AE is able to manage security objects, such as X.509 certificates,
symmetric and asymmetric encryption keys and tokens, as well as providing attribute-
based access control (ABAC) services based on the XACML standard. For authentication,
token-based authentication can be used, which authenticates users with their usernames
and passwords, and obtains a time-limited cryptographically secure token upon successful
authentication. The token can be used for further authentication for a session of limited
duration. Access control is provided through a XACML policy decision point (PDP), which
is a decision engine that evaluates user or administrator defined access control policies
to provide fine-grained access control to the available resources. An advantage of this
authentication and access control approach is that the users can share their tokens with
some trusted entities not only for a limited time, but also a limited set of resources, without
having to share their usernames, passwords or other sensitive security credentials. This
approach is also useful for security evaluation and auditing purposes.
Therefore, the amalgamation of the above-mentioned technologies requires the tuning
of the system on low level and helps achieve data protection, identity and access manage-
ment, and compliance. An organization can build on top of this framework and achieve
high-level security objectives that include governance, trust, architecture, availability and
data lock-in.
5. Performance Metrics
To demonstrate the feasibility of the proposed framework, a proof-of-concept proto-
type was developed and tested over a real-world dataset. Before discussing the complexity
of the proposed framework, the system specifications and dataset description are presented:
5.1. System Specifications
The workstation used for the development and testing is an 11th Generation Intel(R)
Core (TM) i5-1135G7 @ 2.40 GHz with 12 GB RAM. The implementation was done in
Python and the Homomorphic Encryption library used is HElib version 2.1.0 [
30
] over the
Ubuntu operating system.
5.2. Dataset Description
The prototype was tested over a real-world dataset of large genome databases. The
dataset is available at [
31
] and was already used in DNA-based searchable encryption
techniques [
17
]. The dataset contains 10,000 binary DNA sequences. Each sequence is of
2158 bits long.
5.3. Computational Performance
To demonstrate the performance of the prototype, all the phases of the proposed
framework were implemented. However, in future work we will extend the proof of
concept to include the last phase, i.e., data storage on water. Figure 5extends Figure 4
Electronics 2022,11, 818 11 of 15
and highlights the processes that are involved. All the phases are discussed, and the
performance results are presented below:
5.3.1. Encode Data
Encoding the data is the process where the data are firstly converted into binary and
then in their ASCII representation. In the dataset, each tuple is already converted into
bits, so we convert every octet into its decimal representation and then we derive the
corresponding character from there. This helps us reduce the number of data segments
that were to be encrypted and also reduces the storage overhead. The time required for
encoding the bit stream is presented in the Figure 6. For a stream of 2300 bits, the encoding
requires a total of 0.0016 s.
5.3.2. Encrypt Data and Store
The security is reliant on the encryption of the data. For this purpose, we used fully
homomorphic encryption, HeLib. The proposed framework is not dependent upon a
particular variant of homomorphic encryption, so we also refer readers to [
32
] that presents
a comparison of the existing schemes. The authors also discussed the key sizes and different
security parameters. We used HElib version 2.1.0. The encryption time is represented in
Figure 7. It can be seen that for 2300 bits, after encoding, the encryption time is 0.09 bits.
Version February 25, 2022 submitted to Journal Not Specified 11 of 16
5.2. Dataset Description 349
The prototype has been tested over a real-world dataset of large genome databases.
350
The dataset is available at [20] and has already been used in DNA-based Searchable
351
Encryption techniques [17]. The dataset contains 10,000 binary DNA sequences. Each of
352
the sequence is of 2158bits long. 353
5.3. Computational Performance 354
To demonstrate the performance of the prototype, all the phases of the proposed
355
framework have been implemented. However, in future work we will extend the proof of
356
concept to include the last phase, i.e., data storage on water. Figure 5 extends the figure 4
357
and highlights the processes that are involved. All the phases have been discussed and the
358
performance results have been presented below: 359
Figure 5. Process diagram to securely store the data
5.3.1. Encode data 360
Encoding the data is the process where the data is firstly converted into binary and
361
then in its ASCII representation. In the dataset, each tuple is already converted into bits so
362
we convert every octet into its decimal representation and then we derive the corresponding
363
character from there. This helps us reduce the number of data segments that were to be
364
encrypted and also reduces the storage overhead. The time required for encoding the bit
365
stream is presented in the figure 6. For a stream of 2300 bits, the encoding requires a total
366
of 0.0016 seconds. 367
5.3.2. Encrypt data and store 368
The security is reliant on the encryption of the data. For this purpose we have used
369
Fully Homomorphic Encryption HeLib. The proposed framework isn’t dependent upon a
370
particular variant of homomorphic encryption so we also refer readers to [21] that presents
371
a comparison of the existing schemes. The authors have also discussed the key sizes and
372
different security parameters. We have used HElib version 2.1.0. The encryption time is
373
represented in the figure 7. It can be seen that for 2300 bits, after encoding, the encryption
374
time is 0.09 bits. 375
Figure 5. Process diagram to securely store the data.
Electronics 2022,11, 818 12 of 15
Version February 25, 2022 submitted to Journal Not Specified 12 of 16
Figure 6. Computational complexity for encoding
Figure 7. Computational complexity for encryption
5.3.3. Encrypted DNA search 376
Search over the DNA strand is the most important aspect of the proposed architecture
377
as it becomes a challenge to identify the required data segments once the data has been
378
encrypted. The time required to search over 2300 bits homomorphically encrypted is 206.57
379
seconds. 380
5.3.4. Decrypt relevant data 381
The data segments identified as a result of the search need to be decrypted so that the
382
underlying plaintext can be recovered. As shown in figure 8, the decryption time for 2300
383
bits is 0.014 seconds. 384
5.3.5. Decode Data 385
Upon the successful search, once the data has been decrypted, it needs to be decoded
386
to give the original binary representation so that the data is aligned with the original text
387
Figure 6. Computational complexity for encoding.
Version February 25, 2022 submitted to Journal Not Specified 12 of 16
Figure 6. Computational complexity for encoding
Figure 7. Computational complexity for encryption
5.3.3. Encrypted DNA search 376
Search over the DNA strand is the most important aspect of the proposed architecture
377
as it becomes a challenge to identify the required data segments once the data has been
378
encrypted. The time required to search over 2300 bits homomorphically encrypted is 206.57
379
seconds. 380
5.3.4. Decrypt relevant data 381
The data segments identified as a result of the search need to be decrypted so that the
382
underlying plaintext can be recovered. As shown in figure 8, the decryption time for 2300
383
bits is 0.014 seconds. 384
5.3.5. Decode Data 385
Upon the successful search, once the data has been decrypted, it needs to be decoded
386
to give the original binary representation so that the data is aligned with the original text
387
Figure 7. Computational complexity for encryption.
5.3.3. Encrypted DNA Search
Search over the DNA strand is the most important aspect of the proposed architecture,
as it becomes a challenge to identify the required data segments once the data are encrypted.
The time required to search over 2300 bits homomorphically encrypted is 206.57 s.
5.3.4. Decrypt Relevant Data
The data segments identified as a result of the search need to be decrypted so that
the underlying plaintext can be recovered. As shown in Figure 8, the decryption time for
2300 bits is 0.014 s.
Electronics 2022,11, 818 13 of 15
Version February 25, 2022 submitted to Journal Not Specified 13 of 16
Figure 8. Computational complexity for decryption
that was stored. The time required for this operation is presented in the figure 9. For 2300
388
bits the decoding time is 0.006 seconds. 389
Figure 9. Computational complexity for decoding
6. Conclusion and future work 390
The popularity of IoT devices has placed them in a variety of environments and
391
settings. Users are always looking for devices that are faster and increasingly intelligent.
392
IoT devices sense data, store it and possibly make decisions on the data at hand thus the
393
demand for increased secure data storage. Water is known to be most vital compound for
394
man’s well being. Recently, this essential compound has further risen to prominence as
395
researchers explore its use in liquid hard drives to store data on DNA strands. Although,
396
the liquid hard drive has the ability to store terabytes of data on a tablespoon of water/
397
liquid, the storage of sensitive data on the water and liquid could lead to lack of data
398
confidentiality. Furthermore, it has been claimed that water has memory that can lead to
399
potential security and privacy breaches. This article for the first time highlights security and
400
privacy concerns related to data storage on water and the effects that water memory. This
401
Figure 8. Computational complexity for decryption.
5.3.5. Decode Data
Upon the successful search, once the data are decrypted, they need to be decoded
to give the original binary representation so that the data are aligned with the original
text that was stored. The time required for this operation is presented in the Figure 9. For
2300 bits, the decoding time is 0.006 s.
Version February 25, 2022 submitted to Journal Not Specified 13 of 16
Figure 8. Computational complexity for decryption
that was stored. The time required for this operation is presented in the figure 9. For 2300
388
bits the decoding time is 0.006 seconds. 389
Figure 9. Computational complexity for decoding
6. Conclusion and future work 390
The popularity of IoT devices has placed them in a variety of environments and
391
settings. Users are always looking for devices that are faster and increasingly intelligent.
392
IoT devices sense data, store it and possibly make decisions on the data at hand thus the
393
demand for increased secure data storage. Water is known to be most vital compound for
394
man’s well being. Recently, this essential compound has further risen to prominence as
395
researchers explore its use in liquid hard drives to store data on DNA strands. Although,
396
the liquid hard drive has the ability to store terabytes of data on a tablespoon of water/
397
liquid, the storage of sensitive data on the water and liquid could lead to lack of data
398
confidentiality. Furthermore, it has been claimed that water has memory that can lead to
399
potential security and privacy breaches. This article for the first time highlights security and
400
privacy concerns related to data storage on water and the effects that water memory. This
401
Figure 9. Computational complexity for decoding.
6. Conclusions and Future Work
The popularity of IoT devices has placed them in a variety of environments and
settings. Users are always looking for devices that are faster and increasingly intelligent.
IoT devices sense data, store them and possibly make decisions on the data at hand,
thus the demand for increased secure data storage. Water is known to be most vital
compound for man’s well being. Recently, this essential compound has further risen to
prominence as researchers explore its use in liquid hard drives to store data on DNA
strands. Although the liquid hard drive has the ability to store terabytes of data in a
tablespoon of water/liquid, the storage of sensitive data in the water and liquid could
lead to a lack of data confidentiality. Furthermore, it was claimed that water has memory
that can lead to potential security and privacy breaches. This article for the first time
highlighted the security and privacy concerns related to data storage on water and the
effects of water memory. This study also proposed a framework and mitigation strategies to
deter attackers from launching successful attacks on data stored on water and DNA strands.
A proof-of-concept prototype was implemented and tested over a real-world dataset. The
results demonstrated the practicality of the framework. In future, we propose to extend
Electronics 2022,11, 818 14 of 15
this proposition to a fully functional testbed and demonstrate the capability in a real-world
environment.
Author Contributions:
Conceptualization, S.T. and M.R.; methodology, S.T. and H.T.; validation,
H.T., R.T. and H.A.; formal analysis, H.T. and H.A.; data curation, H.T. and R.T.; writing—original
draft preparation, S.T. and R.T.; writing—review and editing, H.T., R.T. and H.A.; supervision, M.R.
All authors have read and agreed to the published version of the manuscript.
Funding: This research received no external funding.
Acknowledgments:
This work was done by the Information Security and Privacy Lab, NUST sup-
ported by the National Centre for Cyber Security, Pakistan, under the project titled “Privacy Preserv-
ing Search over Sensitive Data Stored in the Cloud”.
Conflicts of Interest: The authors declare no conflict of interest.
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