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  <front>
    <journal-meta />
    <article-meta>
      <title-group>
        <article-title>Performance analysis of symmetric encryption algorithms for time-critical cybersecurity application ⋆</article-title>
      </title-group>
      <contrib-group>
        <contrib contrib-type="author">
          <string-name>Oleksandr Kuznetsov</string-name>
          <email>kuznetsov@karazin.ua</email>
          <email>oleksandr.kuznetsov@uniecampus.it</email>
          <xref ref-type="aff" rid="aff0">0</xref>
          <xref ref-type="aff" rid="aff1">1</xref>
          <xref ref-type="aff" rid="aff4">4</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>Yelyzaveta Kuznetsova</string-name>
          <xref ref-type="aff" rid="aff0">0</xref>
          <xref ref-type="aff" rid="aff4">4</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>Emanuele Frontoni</string-name>
          <email>emanuele.frontoni@unimc.it</email>
          <xref ref-type="aff" rid="aff0">0</xref>
          <xref ref-type="aff" rid="aff3">3</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>Marco Arnesano</string-name>
          <email>marco.arnesano@uniecampus.it</email>
          <xref ref-type="aff" rid="aff0">0</xref>
          <xref ref-type="aff" rid="aff1">1</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>Oleksii Smirnov</string-name>
          <email>dr.SmirnovOA@gmail.com</email>
          <xref ref-type="aff" rid="aff0">0</xref>
          <xref ref-type="aff" rid="aff2">2</xref>
        </contrib>
        <aff id="aff0">
          <label>0</label>
          <institution>CPITS-II 2024: Workshop on Cybersecurity Providing in Information</institution>
        </aff>
        <aff id="aff1">
          <label>1</label>
          <institution>Campus University</institution>
          ,
          <addr-line>10 Via Isimbardi, 22060 Novedrate</addr-line>
          ,
          <country country="IT">Italy</country>
        </aff>
        <aff id="aff2">
          <label>2</label>
          <institution>Central Ukrainian National Technical University</institution>
          ,
          <addr-line>8 University ave., 25006 Kropyvnytskyi</addr-line>
          ,
          <country country="UA">Ukraine</country>
        </aff>
        <aff id="aff3">
          <label>3</label>
          <institution>University of Macerata</institution>
          ,
          <addr-line>30/32 Via Crescimbeni, 62100 Macerata</addr-line>
          ,
          <country country="IT">Italy</country>
        </aff>
        <aff id="aff4">
          <label>4</label>
          <institution>V. N. Karazin Kharkiv National University</institution>
          ,
          <addr-line>4 Svobody sq., 61022 Kharkiv</addr-line>
          ,
          <country country="UA">Ukraine</country>
        </aff>
        <aff id="aff5">
          <label>5</label>
          <institution>and Telecommunication Systems II</institution>
        </aff>
      </contrib-group>
      <fpage>82</fpage>
      <lpage>93</lpage>
      <abstract>
        <p>This study presents a comprehensive performance analysis of symmetric encryption algorithms in the context of time-critical cybersecurity applications. We evaluate a diverse set of algorithms, including established standards and emerging ciphers, across multiple performance metrics relevant to resourceconstrained and latency-sensitive environments. Our methodology encompasses rigorous testing of stream encryption speed, packet encryption efficiency, and key/IV setup times on a standardized hardware platform. The results reveal significant variations in algorithm performance across different operational scenarios, highlighting the importance of context-specific algorithm selection. Notably, newer algorithms such as STRUMOK and SNOW 2.0 demonstrate impressive performance across multiple metrics, challenging the dominance of traditional standards in certain application areas. We discuss the implications of our findings for various time-critical applications, including IoT device security, real-time control systems, and secure data aggregation in smart grids. Our analysis underscores the complex trade-offs between security, performance, and resource efficiency inherent in symmetric encryption implementation.</p>
      </abstract>
      <kwd-group>
        <kwd>eol&gt;symmetric encryption</kwd>
        <kwd>performance analysis</kwd>
        <kwd>cryptography</kwd>
        <kwd>cybersecurity</kwd>
        <kwd>encryption speed 1</kwd>
      </kwd-group>
    </article-meta>
  </front>
  <body>
    <sec id="sec-1">
      <title>1. Introduction</title>
      <p>
        The proliferation of interconnected devices and
timesensitive applications has ushered in a new era of
cybersecurity challenges [
        <xref ref-type="bibr" rid="ref1">1</xref>
        ]. As the digital landscape
evolves, the demand for efficient, secure communication in
resource-constrained and latency-critical environments has
intensified. Symmetric encryption algorithms, long
considered the backbone of secure digital communication,
find themselves at a critical juncture, facing unprecedented
demands for both security and performance [
        <xref ref-type="bibr" rid="ref2">2</xref>
        ].
      </p>
      <p>This study embarks on a comprehensive evaluation of
symmetric encryption algorithms, focusing on their
applicability in time-critical cybersecurity scenarios. Our
investigation spans a diverse array of algorithms, from
wellestablished standards to emerging ciphers, each assessed
across multiple performance metrics relevant to
contemporary security challenges.</p>
      <p>
        The imperative for this research stems from the growing
complexity of modern digital ecosystems [
        <xref ref-type="bibr" rid="ref3">3</xref>
        ]. Internet of
Things (IoT) devices, real-time control systems, wireless
sensor networks, and smart grids represent just a fraction of
the applications where the balance between security and
performance is paramount [
        <xref ref-type="bibr" rid="ref4">4</xref>
        ]. In these domains, the
selection of an appropriate encryption algorithm can have
profound implications for system efficiency, energy
consumption, and overall security posture.
      </p>
      <p>Our study aims to bridge the gap between theoretical
cryptography and practical implementation by providing
empirical performance data crucial for informed
decisionmaking in algorithm selection. By examining encryption
speed, memory usage, and setup efficiency across various
operational scenarios, we offer insights that are directly
applicable to the design and optimization of secure systems
in time-sensitive environments.</p>
      <p>The objectives of this research are multifold:</p>
      <p>To provide a rigorous, comparative analysis of
symmetric encryption algorithms across key
performance metrics relevant to time-critical
applications.</p>
      <p>To elucidate the trade-offs between security and
performance inherent in different algorithmic
approaches.</p>
      <p>To explore the implications of our findings for
specific application areas, including IoT security,
real-time control systems, and secure data
aggregation in smart grids.</p>
      <p>To identify emerging trends and future research
directions in the field of symmetric encryption for
time-critical cybersecurity applications.</p>
      <p>Through this comprehensive analysis, we aim to
contribute to the ongoing discourse on cryptographic
implementation in modern digital systems, offering
valuable insights for researchers, system designers, and
security practitioners alike.</p>
    </sec>
    <sec id="sec-2">
      <title>2. Related work</title>
      <p>The field of symmetric encryption has witnessed significant
advancements in recent years, driven by the evolving
demands of modern cybersecurity applications. This section
provides an overview of recent research efforts relevant to
our study of symmetric encryption algorithms in
timecritical scenarios.</p>
      <p>
        Ghafoori and Miyaji (2024) [
        <xref ref-type="bibr" rid="ref5">5</xref>
        ] conducted an in-depth
analysis of higher-order differential-linear cryptanalysis,
focusing on the ChaCha stream cipher. Their work achieved
reduced time complexity for attacks on reduced rounds of
ChaCha, introducing the first higher-order
differentiallinear attacks on ChaCha 6 and ChaCha 7. This study
underscores the ongoing efforts to assess and improve the
security of widely used stream ciphers against advanced
cryptanalytic techniques.
      </p>
      <p>
        In the realm of lightweight cryptography, Huang et al.
(2023) [
        <xref ref-type="bibr" rid="ref6">6</xref>
        ] proposed IVLBC, an involutive lightweight block
cipher designed specifically for IoT applications. Their work
highlights the growing emphasis on developing encryption
algorithms tailored to resource-constrained environments,
a critical consideration in our analysis of algorithm
performance in diverse application scenarios.
      </p>
      <p>
        Kebande (2023) [
        <xref ref-type="bibr" rid="ref7">7</xref>
        ] introduced an extended version of
the ChaCha20 stream cipher, incorporating enhanced
Quarter Round Functions to improve resistance against
differential attacks. This research exemplifies the ongoing
refinement of established encryption algorithms to address
potential vulnerabilities and enhance security in modern
applications.
      </p>
      <p>
        La Scala and Tiwari (2022) [
        <xref ref-type="bibr" rid="ref8">8</xref>
        ] presented a novel
approach to modeling stream and block ciphers as systems
of explicit difference equations over finite fields. Their
work, which includes analysis of ciphers such as Trivium
and KeeLoq, demonstrates the potential of algebraic
methods in assessing cipher security and developing
cryptanalytic techniques.
      </p>
      <p>
        Mishra et al. (2024) [
        <xref ref-type="bibr" rid="ref9">9</xref>
        ] provided a comprehensive
survey of security and cryptographic perspectives in
Industrial Internet of Things (IIoT) environments. Their
work emphasizes the critical role of cryptographic
primitives in modern cyber defenses and highlights the
potential of post-quantum cryptography techniques for
future IIoT security.
      </p>
      <p>
        Urooj et al. (2023) [
        <xref ref-type="bibr" rid="ref10">10</xref>
        ] explored the integration of
asymmetric and symmetric cryptography in wireless sensor
networks, proposing a hybrid approach combining Elliptic
      </p>
      <p>
        Curve Cryptography (ECC) [
        <xref ref-type="bibr" rid="ref11 ref12 ref13 ref14">11–14</xref>
        ] and Advanced
Encryption Standard (AES). Their research underscores the
importance of balancing security and energy efficiency in
resource-constrained network environments.
      </p>
      <p>
        Zhao et al. (2023) [
        <xref ref-type="bibr" rid="ref15">15</xref>
        ] developed a block cipher
identification scheme based on Hamming weight
distribution, addressing the challenge of cryptosystem
recognition in multi-classification scenarios. Their work
demonstrates the application of machine learning
techniques in cryptanalysis and cipher identification.
      </p>
      <p>
        Caforio et al. (2021) [
        <xref ref-type="bibr" rid="ref16">16</xref>
        ] focused on designing
energyoptimal symmetric encryption primitives, introducing the
concept of “Perfect Trees”. Their research aligns closely
with our study’s emphasis on performance optimization in
resource-constrained environments, highlighting the
growing importance of energy efficiency in cryptographic
implementations.
      </p>
      <p>These recent studies collectively illustrate the diverse
challenges and ongoing innovations in the field of
symmetric encryption. From advanced cryptanalytic
techniques to the development of lightweight ciphers for
IoT applications, the research landscape reflects a
continuous effort to enhance the security, efficiency, and
adaptability of encryption algorithms across various
operational contexts. Our study builds upon this foundation,
providing a comprehensive performance analysis of
symmetric encryption algorithms with a specific focus on
time-critical cybersecurity applications.</p>
    </sec>
    <sec id="sec-3">
      <title>3. Background</title>
      <p>The field of symmetric encryption has evolved significantly
since the advent of modern cryptography, driven by
advances in computational capabilities and the
everchanging landscape of security threats. This section
provides a foundational overview of symmetric encryption,
its role in cybersecurity, and the key factors influencing
algorithm performance in time-critical applications.</p>
      <sec id="sec-3-1">
        <title>3.1. Symmetric encryption fundamentals</title>
        <p>Symmetric encryption algorithms utilize a shared secret key
for both encryption and decryption processes. This
approach offers several advantages, including high-speed
operation and relatively low computational overhead,
making it particularly suitable for securing large volumes of
data or time-sensitive communications.</p>
        <p>
          The two primary categories of symmetric encryption
algorithms are [
          <xref ref-type="bibr" rid="ref17">17</xref>
          ]:


        </p>
        <p>Block Ciphers: These algorithms operate on
fixedsize blocks of data, typically 64 or 128 bits.
Examples include the Advanced Encryption
Standard (AES) and its predecessors. Block ciphers
can be employed in various modes of operation,
such as Electronic Codebook (ECB), Cipher Block
Chaining (CBC), and Counter (CTR) mode, each
offering different security and performance
characteristics.</p>
        <p>Stream Ciphers: These algorithms encrypt data on
a bit-by-bit or byte-by-byte basis, generating a
keystream that is combined with the plaintext.
Examples include ChaCha20 and the algorithms in
the eSTREAM portfolio. Stream ciphers are often
favored in scenarios requiring low latency or
where data arrives in a continuous stream.</p>
      </sec>
      <sec id="sec-3-2">
        <title>3.2. Performance considerations in timecritical applications</title>
        <p>
          Several factors influence the performance of symmetric
encryption algorithms in time-critical cybersecurity
applications [
          <xref ref-type="bibr" rid="ref18 ref19">18, 19</xref>
          ]:
        </p>
        <p>Encryption Speed: The number of clock cycles
required to encrypt a byte of data is a critical
metric, directly impacting the algorithm’s
suitability for high-throughput or low-latency
scenarios.</p>
        <p>Memory Usage: The amount of memory required
for algorithm implementation is particularly
relevant in resource-constrained environments,
such as IoT devices or embedded systems.</p>
        <p>Key Setup Time: The efficiency of initializing the
encryption process with a new key affects the
algorithm’s suitability for scenarios requiring
frequent key changes.</p>
        <p>IV/Nonce Setup Time: For algorithms requiring an
initialization vector (IV) or nonce, the speed of this
setup process can be crucial in applications with
frequent session initializations.</p>
        <p>Power Consumption: While not directly measured
in this study, power consumption correlates with
computational efficiency and is a critical
consideration for battery-powered devices.
3.3.</p>
      </sec>
      <sec id="sec-3-3">
        <title>Evolving requirements in modern cybersecurity</title>
        <p>
          The landscape of cybersecurity is continually evolving,
driven by factors such as [
          <xref ref-type="bibr" rid="ref20">20</xref>
          ]:
        </p>
        <p>Increasing Data Volumes: The exponential growth
in data generation and transmission necessitates
encryption solutions capable of handling high
throughput without introducing significant
latency.</p>
        <p>Resource Constraints: The proliferation of IoT and
edge computing devices has heightened the need
for efficient encryption algorithms that can
operate effectively on platforms with limited
computational resources and power budgets.</p>
        <p>Quantum Computing Threat: The potential
development of large-scale quantum computers
poses a significant threat to many current
cryptographic systems, driving research into
quantum-resistant algorithms.</p>
        <p>
          Regulatory Compliance: Evolving data protection
regulations impose stringent requirements on data
security, influencing the selection and
implementation of encryption algorithms across
various industries.









Recent developments in the field of symmetric encryption
include [
          <xref ref-type="bibr" rid="ref21 ref9">9, 21</xref>
          ]:
        </p>
        <p>Lightweight Cryptography: The design of algorithms
specifically optimized for resource-constrained
environments, balancing security with minimal
computational and energy requirements.</p>
        <p>Authenticated Encryption: The integration of
authentication mechanisms within encryption
algorithms to provide both confidentiality and
integrity in a single operation.</p>
        <p>Post-Quantum Cryptography: Research into
symmetric encryption algorithms resistant to
attacks by quantum computers, focusing on
increasing key sizes and developing new
algorithmic approaches.</p>
        <p>Homomorphic Encryption: The development of
encryption schemes that allow computations to be
performed on encrypted data without decryption,
opening new possibilities for secure data
processing in untrusted environments.







</p>
        <p>
          Based on these criteria, we selected the following
algorithms for evaluation [
          <xref ref-type="bibr" rid="ref23">23</xref>
          ]: AES (128-bit and 256-bit
variants); SNOW 2.0 (128-bit and 256-bit variants); Salsa20;
HC-128 and HC-256; MICKEY-128; Rabbit; SOSEMANUK;
TRIVIUM; STRUMOK; DECIMv2. This selection
        </p>
        <p>Understanding these fundamental concepts,
performance considerations, and emerging trends is crucial
for contextualizing the results of our performance analysis
and their implications for time-critical cybersecurity
applications. This background sets the stage for a nuanced
examination of how different symmetric encryption
algorithms perform under various operational scenarios and
their suitability for diverse application domains.</p>
      </sec>
    </sec>
    <sec id="sec-4">
      <title>4. Methodology</title>
      <p>This section outlines the comprehensive approach
employed in our study to evaluate the performance of
lightweight symmetric encryption algorithms in
timecritical cybersecurity applications. Our methodology is
designed to provide a rigorous, reproducible framework for
assessing the efficiency and suitability of these algorithms
across various metrics relevant to resource-constrained and
latency-sensitive environments.</p>
      <sec id="sec-4-1">
        <title>4.1. Algorithm selection criteria</title>
        <p>
          We selected a diverse set of symmetric encryption
algorithms based on the following criteria [
          <xref ref-type="bibr" rid="ref22">22</xref>
          ]:
        </p>
        <p>Relevance to current cybersecurity practices.</p>
        <p>Potential for application in resource-constrained
environments.</p>
        <p>Variety in design principles and structural
characteristics.</p>
        <p>Inclusion of both well-established and emerging
algorithms.
encompasses a range of block ciphers, stream ciphers, and
hybrid designs, providing a comprehensive view of the
current state of symmetric encryption.</p>
      </sec>
      <sec id="sec-4-2">
        <title>4.2. Testing environment</title>
        <p>Our evaluation was conducted on a system with the
following specifications:</p>
        <p>Implementation Verification: We used verified
implementations of each algorithm, ensuring
consistency with their respective specifications.
Stream Encryption Test: Each algorithm encrypted
1 Gigabyte of data, with performance measured
using the RDTSC (Read Time-Stamp Counter)
instruction for precise cycle counting.</p>
        <p>Packet Encryption Test: We tested three packet
sizes (40, 576, and 1500 bytes) to simulate various
network traffic patterns. For each size, we
encrypted multiple blocks under different keys to
account for real-world usage scenarios.</p>
        <p>Key and IV Setup Tests: We performed multiple
key and IV setups for each algorithm, measuring
the time taken for these critical initialization
processes.</p>
        <p>Data Collection and Analysis: Performance data
was collected over multiple runs to ensure
statistical significance. We calculated average
Stream Encryption Speed: Measured in cycles per
byte and megabits per second (Mbps).</p>
        <p>Packet Encryption Speed: Evaluated for packet
sizes of 40, 576, and 1500 bytes, reported in cycles
per packet, cycles per byte, and Mbps.</p>
        <p>Key Setup Speed: Measured in cycles per setup and
setups per second.</p>
        <p>IV (Initialization Vector) Setup Speed: Measured in
cycles per setup and setups per second.</p>
        <p>These metrics were chosen to provide a comprehensive
view of algorithm performance across different operational
scenarios.</p>
      </sec>
      <sec id="sec-4-3">
        <title>4.4. Evaluation process</title>
        <p>
          Our evaluation process consisted of the following steps [
          <xref ref-type="bibr" rid="ref24">24</xref>
          ]:
        </p>
        <p>To ensure consistency and reproducibility, all tests were
performed under controlled conditions, with minimal
background processes running.</p>
      </sec>
      <sec id="sec-4-4">
        <title>4.3. Performance metrics</title>
        <p>
          We evaluated the algorithms
performance metrics [
          <xref ref-type="bibr" rid="ref24">24</xref>
          ]:
across
several key













        </p>
      </sec>
      <sec id="sec-4-5">
        <title>4.5. Evaluation tools</title>
        <p>We developed custom benchmarking tools to ensure
consistent and accurate measurement across all algorithms.
These tools were designed to minimize overhead and
provide precise timing information. The core of our testing
suite utilized the following components:</p>
        <p>A high-resolution timer using the RDTSC
instruction for cycle-accurate measurements.</p>
        <p>Memory management routines to ensure
consistent cache behavior across tests.</p>
        <p>Data generation functions to provide consistent
input across all algorithms.</p>
        <p>Output verification routines to ensure the
correctness of encryption operations.</p>
      </sec>
      <sec id="sec-4-6">
        <title>4.6. Reproducibility measures</title>
        <p>To ensure the reproducibility of our results, we have taken
the following measures:









performance metrics and standard deviations to
account for system variability.</p>
        <p>Comparative Analysis: We analyzed the collected
data to compare the performance of the algorithms
across different metrics and usage scenarios.</p>
        <p>Detailed documentation of all testing procedures
and environment configurations.</p>
        <p>Use of open-source implementations where
available, with clear version information.</p>
        <p>Publication of our custom benchmarking tools and
scripts (available upon request).</p>
        <p>Multiple test runs with statistical analysis to
account for system variability.</p>
        <p>By adhering to these methodological principles, we aim to
provide a comprehensive and reliable evaluation of
symmetric encryption algorithms, offering valuable insights
for the selection and implementation of these algorithms in
time-critical cybersecurity applications.</p>
      </sec>
    </sec>
    <sec id="sec-5">
      <title>5. Overview of selected encryption algorithms</title>
      <p>This section provides a concise overview of the symmetric
encryption algorithms selected for our performance
analysis. Each algorithm is described in terms of its core
structure, key characteristics, and potential applications in
time-critical cybersecurity scenarios.</p>
      <sec id="sec-5-1">
        <title>5.1. Advanced encryption standard</title>
        <p>
          AES, standardized by NIST in 2001, remains a cornerstone
of modern cryptography. We evaluate both 128-bit and
256bit key variants [
          <xref ref-type="bibr" rid="ref25 ref26">25, 26</xref>
          ].
        </p>
        <p>Structure: AES employs a substitution-permutation
network with a fixed block size of 128 bits. It operates
through a series of rounds, each comprising four stages:
SubBytes, ShiftRows, MixColumns, and AddRoundKey.</p>
        <p>Key Characteristics:




















</p>
        <p>
          Applications: Suitable for high-speed encryption in
software-based systems, particularly in network security.
5.3. Salsa20
Designed by Daniel J. Bernstein in 2005, Salsa20 aims for
high speed across various platforms [
          <xref ref-type="bibr" rid="ref29 ref30">29, 30</xref>
          ].
        </p>
        <p>Structure: Operates on 64-byte blocks using a series of
quarter-round functions, consisting of 32-bit addition, XOR,
and rotation operations.</p>
        <p>Key Characteristics:</p>
        <p>Simple design facilitating analysis and
implementation.</p>
        <p>Supports 128-bit and 256-bit keys with a 64-bit nonce.</p>
        <p>No known practical attacks compromise its security.</p>
        <p>
          Applications: Well-suited for applications requiring
fast, secure encryption on diverse hardware platforms.
5.4. HC-128 and HC-256
Part of the eSTREAM portfolio, these stream ciphers were
designed by Hongjun Wu [
          <xref ref-type="bibr" rid="ref31">31</xref>
          ].
        </p>
        <p>Structure: Utilize two secret tables, each containing 512
32-bit elements, updated during keystream generation.</p>
        <p>Key Characteristics:</p>
        <p>Wide-spread adoption and extensive scrutiny.</p>
        <p>Efficient hardware implementation.</p>
        <p>Varying number of rounds based on key size (10
for 128-bit, 14 for 256-bit).</p>
        <p>
          Applications: Widely used in secure communications,
financial transactions, and data storage.
5.2. SNOW 2.0
SNOW 2.0, an evolution of the SNOW stream cipher, is
designed for software efficiency [
          <xref ref-type="bibr" rid="ref27 ref28">27, 28</xref>
          ].
        </p>
        <p>Structure: Combines a Linear Feedback Shift Register
(LFSR) with a Finite State Machine (FSM). The LFSR has 16
stages, each holding a 32-bit word, while the FSM contains
two 32-bit registers.</p>
        <p>Key Characteristics:</p>
        <p>High efficiency in software implementations.</p>
        <p>Support for both 128-bit and 256-bit key sizes.</p>
        <p>Strong resistance against known attacks on stream
ciphers.</p>
        <p>Excellent performance in software, especially with
large caches.</p>
        <p>HC-128 uses a 128-bit key and IV, HC-256 uses
256-bit for both.</p>
        <p>Strong security guarantees with no known
practical attacks.</p>
        <p>Applications: Ideal for software-based encryption in
systems with sufficient memory resources.</p>
        <p>Applications: Suitable for software-based encryption in
various network security scenarios.</p>
      </sec>
      <sec id="sec-5-2">
        <title>5.8. TRIVIUM</title>
        <p>
          Designed by Christophe De Cannière and Bart Preneel,
TRIVIUM aims for simplicity and high performance [
          <xref ref-type="bibr" rid="ref33 ref36">33, 36</xref>
          ].
        </p>
        <p>Structure: Internal state of 288 bits stored in three shift
registers of different lengths.</p>
        <p>Key Characteristics:</p>
      </sec>
      <sec id="sec-5-3">
        <title>5.6. Rabbit</title>
        <p>
          Developed by Cryptico A/S, Rabbit is a high-speed stream
cipher [
          <xref ref-type="bibr" rid="ref34">34</xref>
          ].
        </p>
        <p>Structure: Based on iterating a system of non-linear
functions, maintaining an internal state of 513 bits.</p>
        <p>Key Characteristics:
128-bit key and 64-bit IV.</p>
        <p>Designed for high speed in both software and
hardware.</p>
        <p>Compact state size suitable for
memoryconstrained environments.</p>
        <p>Applications: Excellent for scenarios requiring fast
encryption with limited memory resources.</p>
      </sec>
      <sec id="sec-5-4">
        <title>5.7. SOSEMANUK</title>
        <p>
          Based on the design principles of SNOW 2.0, SOSEMANUK
aims for software efficiency [
          <xref ref-type="bibr" rid="ref34">34</xref>
          ].
        </p>
        <p>Structure: Combines an LFSR with an FSM, inspired by
the SERPENT block cipher.</p>
        <p>Key Characteristics:</p>
        <p>Supports 128-bit and 256-bit keys, with 64-bit to
128-bit IV.</p>
        <p>Designed for high efficiency in software
implementations.</p>
        <p>Strong resistance against known cryptanalytic
attacks.
Fig. 1 presents the stream encryption performance for all
tested algorithms, sorted by encryption speed in descending
order.





</p>
        <p>Applications: Ideal for hardware-based encryption in
resource-constrained environments.</p>
      </sec>
      <sec id="sec-5-5">
        <title>5.9. STRUMOK</title>
        <p>
          A relatively new stream cipher designed for high-speed
software implementations [
          <xref ref-type="bibr" rid="ref37 ref38">37, 38</xref>
          ].
        </p>
        <p>Structure: Optimized for 64-bit processors, utilizing a
combination of simple operations for high speed.</p>
        <p>Key Characteristics:
256-bit or 512-bit key and 256-bit IV.</p>
        <p>Designed specifically for high performance on
modern processors.</p>
        <p>Ongoing evaluation by the cryptographic
community.</p>
        <p>Applications: Suitable for high-performance edge
computing and other scenarios requiring fast
softwarebased encryption.
5.10.</p>
      </sec>
      <sec id="sec-5-6">
        <title>DECIMv2</title>
        <p>
          An improved version of the original DECIM stream cipher,
designed for lightweight applications [
          <xref ref-type="bibr" rid="ref39">39</xref>
          ].
        </p>
        <p>Structure: Employs a combination of a non-linear
feedback shift register (NFSR) and a linear feedback shift
register (LFSR).</p>
        <p>Key Characteristics:
80-bit key and 80-bit IV.</p>
        <p>Designed for hardware efficiency in constrained
environments.</p>
        <p>Improved security compared to its predecessor.</p>
        <p>Applications: Well-suited for resource-constrained
hardware, such as RFID systems or lightweight IoT devices.</p>
        <p>This diverse selection of algorithms provides a
comprehensive basis for our performance analysis, covering
a wide range of design principles and potential applications
in time-critical cybersecurity scenarios.</p>
      </sec>
    </sec>
    <sec id="sec-6">
      <title>6. Performance analysis results</title>
      <p>This section presents a comprehensive analysis of the
performance metrics obtained from our rigorous evaluation
of the selected symmetric encryption algorithms. We
provide a detailed comparison of encryption speeds,
memory usage, and other critical performance indicators.
Furthermore, we discuss the inherent trade-offs between
security and performance, offering insights into the
suitability of each algorithm for various time-critical
cybersecurity applications.</p>
      <sec id="sec-6-1">
        <title>6.1. Presentation of performance metrics</title>
        <p>Our analysis focuses on four key performance metrics:
stream encryption speed, packet encryption speed, key
setup speed, and IV setup speed. These metrics provide a
holistic view of each algorithm’s efficiency across different
operational scenarios.</p>
        <p>DECIMv2
MICKEY-128</p>
        <p>AES-256
AES-128
Salsa20</p>
        <p>Rabbit
TRIVIUM</p>
        <p>HC-256</p>
        <p>SOSEMANUK
SNOW 2.0 (128-bit)
SNOW 2.0 (256-bit)</p>
        <p>STRUMOK</p>
        <p>HC-128</p>
        <p>DECIMv2
MICKEY-128</p>
        <p>AES-256
AES-128
Salsa20</p>
        <p>Rabbit
TRIVIUM</p>
        <p>HC-256</p>
        <p>SOSEMANUK
SNOW 2.0 (128-bit)
SNOW 2.0 (256-bit)</p>
        <p>STRUMOK</p>
        <p>HC-128
1
10
100
1000
10000
1
10
100
1000
10000
100000
As evident from Fig. 1, HC-128 demonstrates exceptional
performance in stream encryption, achieving the highest
throughput of 21,550.26 Mbps with the lowest cycles per
byte (1.41). STRUMOK and both variants of SNOW 2.0 also
exhibit impressive performance, with throughputs
exceeding 12,000 Mbps. These results suggest that these
algorithms are particularly well-suited for applications
requiring high-speed stream encryption, such as real-time
video streaming or high-bandwidth network traffic
encryption.</p>
        <p>Interestingly, the widely-used AES algorithm,
particularly its 256-bit variant, shows comparatively lower
performance in stream encryption. This observation
underscores the potential benefits of exploring alternative
algorithms for scenarios requiring high-throughput stream
encryption in time-critical applications.</p>
      </sec>
      <sec id="sec-6-2">
        <title>6.3. Packet encryption performance</title>
        <p>Key Setup (cycles/setup)
10
100
1000
10000
The packet encryption results reveal interesting shifts in
performance compared to stream encryption. STRUMOK,
SNOW 2.0, and SOSEMANUK demonstrate superior
performance in packet encryption, maintaining high
throughput across various packet sizes. These algorithms
show particular promise for applications dealing with
diverse packet sizes, such as secure IoT communication or
virtual private networks (VPNs).</p>
        <p>Notably, HC-128, which excelled in stream encryption,
shows a significant performance drop in packet encryption.
This disparity highlights the importance of considering both
stream and packet encryption performance when selecting
an algorithm for time-critical applications.</p>
      </sec>
      <sec id="sec-6-3">
        <title>6.4. Key and IV setup efficiency</title>
        <p>

0.1
1
10
100
1000</p>
      </sec>
      <sec id="sec-6-4">
        <title>6.5. Comparative analysis across different algorithms</title>
        <p>The performance metrics presented in Figs. 1–3 reveals
several key insights:</p>
        <p>Stream Encryption Efficiency: HC-128,
STRUMOK, and SNOW 2.0 consistently
demonstrate superior performance in stream
encryption, making them ideal candidates for
high-throughput applications.</p>
        <p>Packet Encryption Variability: The relative
performance of algorithms shifts when
considering packet encryption, with STRUMOK
and SNOW 2.0 maintaining high efficiency across
different packet sizes.</p>
        <p>Setup Speed Trade-offs: Algorithms like Salsa20
and AES show a stark contrast between their key
and IV setup performance, with very fast IV setup
but slower key setup operations.</p>
        <p>Consistency Across Metrics: SNOW 2.0 and
STRUMOK demonstrate consistently high
performance across all metrics, suggesting their
versatility for various time-critical applications.
Resource-Constrained Scenarios: Lightweight
algorithms like TRIVIUM and MICKEY-128 show
competitive performance in certain metrics,
making them suitable for resource-constrained
environments.</p>
      </sec>
      <sec id="sec-6-5">
        <title>6.6. Discussion of trade-offs between security and performance</title>
        <p>The performance analysis reveals several important
tradeoffs between security and efficiency:




</p>
        <p>Key Size vs. Speed: Generally, algorithms with
larger key sizes (e.g., AES-256) show lower
encryption speeds compared to their shorter key
counterparts. This trade-off is particularly evident
in time-critical applications where every cycle
counts.</p>
        <p>Complexity vs. Efficiency: More complex
algorithms like AES, which involve multiple
rounds of substitution and permutation, tend to
have lower throughput compared to simpler
designs like HC-128 or STRUMOK. However, this
complexity often correlates with higher resistance
to cryptanalysis.</p>
        <p>Setup Efficiency vs. Security: Algorithms with very
fast setup times (e.g., DECIMv2 for key setup) may be
more vulnerable to certain types of attacks if keys are
changed frequently. Conversely, algorithms with
slower setup times often incorporate a more
thorough mixing of the key material.</p>
        <p>Stream vs. Packet Performance: Some algorithms
excel in stream encryption but show reduced
efficiency in packet encryption (e.g., HC-128). This
trade-off is crucial when selecting algorithms for
specific network protocols or data transmission
patterns.</p>
        <p>Memory Usage vs. Speed: Algorithms that use
larger internal states or lookup tables (e.g.,
HC256) often achieve higher speeds but may be less
suitable for memory-constrained devices.</p>
        <p>In conclusion, the selection of an encryption algorithm
for time-critical cybersecurity applications must carefully
balance these performance metrics against the specific
security requirements and resource constraints of the target
system. The data presented here provides a foundation for
making informed decisions in algorithm selection,
highlighting the need for a nuanced approach that considers
the full spectrum of performance characteristics in the
context of the intended application.</p>
      </sec>
    </sec>
    <sec id="sec-7">
      <title>7. Application scenarios</title>
      <p>The performance characteristics of symmetric encryption
algorithms have significant implications for their suitability
in various time-critical cybersecurity applications. This
section examines the relevance of our findings to specific
application areas, highlighting how the performance
tradeoffs of different algorithms align with the unique
requirements of each domain.</p>
      <sec id="sec-7-1">
        <title>7.1. IoT device security</title>
        <p>
          IoT devices present a unique set of challenges for
encryption implementation due to their resource
constraints and diverse operational environments. Our
analysis reveals several key considerations for IoT device
security [
          <xref ref-type="bibr" rid="ref9">9</xref>
          ]:







        </p>
        <p>Resource Efficiency: Lightweight algorithms such
as TRIVIUM and MICKEY-128 demonstrate
potential for IoT applications due to their efficient
performance on resource-constrained hardware.
TRIVIUM, in particular, shows promising results
in packet encryption (5.93 cycles/byte), making it
suitable for IoT devices that transmit small data
packets intermittently.</p>
        <p>Energy Consumption: The correlation between
cycles per byte and energy consumption suggests
that algorithms like STRUMOK and SNOW 2.0,
with their low cycles per byte in both stream and
packet encryption, could be beneficial for
batterypowered IoT devices where energy efficiency is
crucial.</p>
        <p>Flexibility: The variability in IoT device
capabilities necessitates a flexible approach to
encryption. For more powerful IoT edge devices,
algorithms like HC-128 or STRUMOK could
provide high-speed encryption for data streams,
while resource-constrained sensors might benefit
from the efficiency of TRIVIUM or the versatility
of SNOW 2.0.</p>
        <p>Key Management: The rapid key setup speed of
algorithms like STRUMOK (15,217,391.30 setups/sec)
could be advantageous in IoT networks requiring
frequent key rotations to maintain security in
potentially compromised environments.</p>
        <p>Implementation Recommendation: For heterogeneous
IoT networks, a hybrid approach using SNOW 2.0 for more
capable devices and TRIVIUM for highly constrained
sensors could provide a balance of security and efficiency
across the network.</p>
      </sec>
      <sec id="sec-7-2">
        <title>7.2. Real-time control systems</title>
        <p>
          Real-time control systems, such as those found in industrial
automation or autonomous vehicles, require encryption
solutions that can operate within strict timing constraints
without introducing significant latency. Our findings
suggest the following considerations [
          <xref ref-type="bibr" rid="ref40">40</xref>
          ]:
        </p>
        <p>Low Latency: The exceptional performance of
HC128 in stream encryption (1.41 cycles/byte) makes
it a strong candidate for real-time systems dealing
with continuous data streams, such as sensor feeds
in autonomous vehicles.</p>
        <p>Deterministic Performance: Algorithms with
consistent performance across different data sizes,
like SNOW 2.0 and STRUMOK, are well-suited for
real-time control systems where predictable
timing is critical.</p>
        <p>Packet Encryption Efficiency: For systems
communicating via network packets, STRUMOK’s
superior performance in packet encryption (3.13
cycles/byte) could minimize encryption-induced
delays in command and control communications.
Setup Speed: The rapid IV setup times of
algorithms like AES (50,000,000 setups/sec for
AES-128) could be beneficial in scenarios requiring
frequent session initializations without
compromising overall system responsiveness.</p>
        <p>Implementation Recommendation: For real-time control
systems with varying data flow characteristics, a
combination of HC-128 for stream data and STRUMOK for
packet-based communication could provide optimal
performance while maintaining robust security.</p>
      </sec>
      <sec id="sec-7-3">
        <title>7.3. Secure communication in wireless sensor networks</title>
        <p>
          Wireless Sensor Networks (WSNs) face unique challenges
in implementing secure communication due to their
distributed nature, limited resources, and often harsh
operational environments. Our analysis highlights several
important factors [
          <xref ref-type="bibr" rid="ref41 ref42">41, 42</xref>
          ]:
        </p>
        <p>Energy Efficiency: The low cycles per byte of
algorithms like SNOW 2.0 and SOSEMANUK in
packet encryption (3.55 and 3.85 cycles/byte,
respectively) could translate to lower energy
consumption, crucial for extending the operational
life of battery-powered sensor nodes.</p>
        <p>Lightweight Implementation: TRIVIUM's simple
design and efficient hardware implementation
make it an attractive option for WSNs with highly
constrained sensor nodes.</p>
        <p>Scalability: The strong performance of STRUMOK
across both stream and packet encryption suggests
its suitability for heterogeneous WSNs where
some nodes may handle aggregated data streams
while others transmit individual sensor readings.
Resilience to Packet Loss: In WSNs prone to packet
loss, the independent encryption of packets
facilitated by algorithms with efficient IV setup,
such as Salsa20, could enhance network resilience
by minimizing the impact of lost packets on
subsequent communications.</p>
        <p>Implementation Recommendation: A tiered approach
using TRIVIUM for the most constrained sensor nodes and
SNOW 2.0 for cluster heads or data aggregation points could
provide a balance of efficiency and security across the WSN.</p>
      </sec>
      <sec id="sec-7-4">
        <title>7.4. Privacy-preserving data aggregation in smart grids</title>
        <p>
          Smart grid systems require secure, privacy-preserving
mechanisms for data aggregation and analysis. The
performance characteristics of encryption algorithms have
significant implications for balancing privacy, efficiency,
and scalability in these systems [
          <xref ref-type="bibr" rid="ref43">43</xref>
          ]:
        </p>
        <p>High-throughput Encryption: The exceptional
stream encryption performance of HC-128
(21550.26 Mbps) could be leveraged for securing
high-volume data flows from smart meters to
aggregation points without introducing significant
latency.






Versatility: The consistently high performance of
SNOW 2.0 and STRUMOK across various metrics
suggests their suitability for the diverse workloads
encountered in edge computing scenarios.</p>
        <p>Computational Efficiency: The low cycles per byte
achieved by top-performing algorithms could
translate to reduced computational overhead,
crucial for maintaining the low-latency promise of
edge computing.</p>
        <p>Adaptability: The range of performance profiles
observed across our tested algorithms suggests the
potential for adaptive encryption strategies in
edge environments, dynamically selecting
algorithms based on current processing loads and
security requirements.</p>
        <p>Implementation Recommendation: Further
research into the performance of these algorithms
on typical edge computing hardware is warranted,
with particular attention to the balance between
encryption speed and overall application
performance in resource-shared environments.</p>
        <p>In conclusion, the performance characteristics of
symmetric encryption algorithms have profound
implications for their deployment in time-critical
cybersecurity applications. The diverse requirements of IoT
security, real-time control systems, wireless sensor
networks, smart grids, and edge computing necessitate
careful consideration of algorithm selection and
implementation strategies. Our findings provide a





</p>
        <p>Efficient Packet Processing: STRUMOK's strong
performance in packet encryption (9730.46 Mbps)
makes it suitable for securing the diverse packet
sizes typically encountered in smart grid
communication protocols.</p>
        <p>Homomorphic Properties: While not directly
measured in our study, the potential for partial
homomorphic operations in some stream ciphers
could be exploited for privacy-preserving
aggregation. Further research into the
homomorphic properties of high-performing
algorithms like SNOW 2.0 or STRUMOK could
yield valuable insights for smart grid applications.
Key Agility: The rapid key setup capabilities of
algorithms like STRUMOK and SNOW 2.0
facilitate frequent key rotations, enhancing
longterm security in the persistent threat environment
of smart grid infrastructure.</p>
        <p>Implementation Recommendation: A hybrid system
using HC-128 for high-volume data streams and STRUMOK
for packet-based communications could provide a robust,
efficient encryption solution for smart grid data
aggregation.</p>
      </sec>
      <sec id="sec-7-5">
        <title>7.5. Secure data processing in edge computing</title>
        <p>
          While not the primary focus of this study, our findings have
relevant implications for secure data processing in edge
computing environments [
          <xref ref-type="bibr" rid="ref43">43</xref>
          ]:
foundation for informed decision-making in these critical
application areas, highlighting the need for tailored, often
hybrid approaches to encryption that balance security,
efficiency, and application-specific constraints.
        </p>
      </sec>
    </sec>
    <sec id="sec-8">
      <title>8. Discussion</title>
      <p>The comprehensive analysis of symmetric encryption
algorithms presented in this study reveals several key
insights with significant implications for time-critical
cybersecurity applications:





</p>
      <p>Performance Variability: Our results demonstrate
substantial variability in algorithm performance
across different metrics. This variability
underscores the importance of selecting
encryption algorithms based on specific
application requirements rather than relying on
generalized performance claims.</p>
      <p>Trade-offs between Security and Efficiency: The
inverse relationship often observed between key
size and encryption speed highlights the ongoing
challenge of balancing security with performance
in resource-constrained environments. This
tradeoff is particularly evident in the comparison
between AES variants and newer, streamlined
algorithms like STRUMOK and SNOW 2.0.</p>
      <p>Emergence of Specialized Algorithms: The strong
performance of algorithms designed for specific
scenarios (e.g., TRIVIUM for hardware
implementation, HC-128 for software-based
stream encryption) suggests a trend towards more
specialized cryptographic solutions. This
specialization could lead to more efficient security
implementations in diverse application areas.</p>
      <p>Importance of Comprehensive Evaluation: The
discrepancies observed between stream and packet
encryption performance for some algorithms
(notably HC-128) emphasize the need for
comprehensive evaluation across multiple metrics
when selecting encryption solutions for complex
systems.</p>
      <p>Potential for Adaptive Encryption Strategies: The
varied performance profiles of the tested
algorithms across different metrics suggest the
potential for adaptive encryption strategies that
dynamically select algorithms based on current
system conditions and security requirements.</p>
      <p>Challenges in Standardization: The superior
performance of newer algorithms like STRUMOK
in certain metrics poses challenges for
standardization efforts, as it suggests the need for
periodic re-evaluation and potential updates to
cryptographic standards to incorporate emerging,
high-performance algorithms.</p>
      <p>These findings have broad implications for the design
and implementation of secure systems in various domains,
from IoT and edge computing to smart grids and real-time
control systems. They highlight the need for a nuanced,
context-aware approach to cryptographic implementation
in time-critical applications.</p>
    </sec>
    <sec id="sec-9">
      <title>9. Conclusions</title>
      <p>This study provides a comprehensive performance analysis
of symmetric encryption algorithms in the context of
timecritical cybersecurity applications. Through rigorous testing
and evaluation, we have identified key performance
characteristics of a diverse set of algorithms, ranging from
well-established standards like AES to emerging ciphers like
STRUMOK.</p>
      <p>Our findings reveal that no single algorithm excels
across all performance metrics, underscoring the
importance of tailored encryption strategies for specific
application scenarios. Notably, newer algorithms such as
STRUMOK and SNOW 2.0 demonstrate impressive
performance across multiple metrics, challenging the
dominance of traditional standards in certain application
areas.</p>
      <p>The analysis of application scenarios highlights the
potential for significant performance improvements
through the strategic selection and implementation of
encryption algorithms. In IoT environments, for instance,
the use of lightweight algorithms like TRIVIUM could
enhance security without overburdening
resourceconstrained devices. Similarly, the high-speed encryption
capabilities of HC-128 and STRUMOK offer promising
solutions for real-time control systems and smart grid data
aggregation.</p>
      <p>However, this study also reveals the complexities
involved in balancing security, performance, and resource
efficiency. The trade-offs between key size, encryption
speed, and setup efficiency necessitate careful consideration
in algorithm selection, particularly in heterogeneous
environments with diverse security requirements.</p>
      <p>Looking forward, our results suggest several directions
for future research:



</p>
      <p>Further investigation into the performance
characteristics of emerging algorithms on diverse
hardware platforms, particularly in edge
computing environments.</p>
      <p>Exploration of adaptive encryption strategies that
leverage the strengths of multiple algorithms to
optimize security and performance dynamically.
Development of standardized benchmarking
methodologies for evaluating encryption
performance in time-critical applications,
facilitating more direct comparisons between
studies.</p>
      <p>Investigation of the energy consumption
implications of different encryption algorithms,
particularly in the context of battery-powered
devices in IoT and WSN scenarios.</p>
      <p>In conclusion, this study contributes to the ongoing
dialogue on the selection and implementation of symmetric
encryption algorithms in time-critical cybersecurity
applications. By providing a comprehensive performance
analysis and discussing its implications across various
application scenarios, we aim to facilitate more informed
decision-making in the design and deployment of secure
systems in an increasingly interconnected and
timesensitive digital landscape.</p>
    </sec>
    <sec id="sec-10">
      <title>Acknowledgments</title>
      <p>
</p>
      <p>This project has received funding from the
European Union’s Horizon 2020 research and
innovation program under the Marie
SkłodowskaCurie grant agreement No. 101007820 - TRUST.
This publication reflects only the author’s view
and the REA is not responsible for any use that
may be made of the information it contains.</p>
    </sec>
  </body>
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