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    <journal-meta />
    <article-meta>
      <title-group>
        <article-title>Using the Flawed Codes In Niederreiter Crypto-Code Structure</article-title>
      </title-group>
      <contrib-group>
        <contrib contrib-type="author">
          <string-name>Oleksii Tsyhanenko</string-name>
          <email>oleksii.tsyhanenko@hneu.net</email>
          <xref ref-type="aff" rid="aff0">0</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>Stanislav Milevskyi</string-name>
          <email>stanislav.milevskiy@hneu.net</email>
          <xref ref-type="aff" rid="aff0">0</xref>
        </contrib>
        <aff id="aff0">
          <label>0</label>
          <institution>dept. of cybersecurity and information technology Simon Kuznets Kharkiv National University of Economics Kharkiv</institution>
          ,
          <country country="UA">Ukraine</country>
        </aff>
      </contrib-group>
      <abstract>
        <p>-the paper highlights basis of methods for constructing flawed codes and approaches for using the Niederreiter hybrid crypto-code structure on modified elliptic codes. Practical algorithms are proposed for using the MV2 damage mechanism in the Niederreiter crypto-code structure on modified elliptic codes, which makes it possible to implement a hybrid crypto-code structure.</p>
      </abstract>
      <kwd-group>
        <kwd>modified crypto-code system Niederreiter</kwd>
        <kwd>cryptocode construction</kwd>
        <kwd>confidentiality</kwd>
        <kwd>integrity</kwd>
      </kwd-group>
    </article-meta>
  </front>
  <body>
    <sec id="sec-1">
      <title>-</title>
      <p>INTRODUCTION</p>
      <p>Today, cybersecurity can be fully considered an important
aspect of any society. With the rapid development of the
Internet information environment, the complexity of
information protection against unauthorized access, the
growing vulnerabilities of critical systems to hybrid
cyberattacks is a significant problem for various users.</p>
      <p>In addition, despite the fact that most organizations are
improving information security systems, cybercriminals
continue to find ways to circumvent them by carrying out
destructive measures. Information security involves achieving
and maintaining security features in user resources aimed at
preventing relevant cyber threats. As a result, the
development of quality software products and national
production will increase the level of cybersecurity of the state.</p>
      <p>According to experts, NIST USA one of the promising
areas is the use of crypto-code schemes McEliece and
Niederreiter. Their classic variations should not be used in
Internet technologies due to their vulnerabilities and high
energy consumption in practice. Therefore, it is advisable to
develop a crypto-code structure (CCS) of Niederreiter using
flawed codes, which will reduce the field strength to GF (24),
with a guaranteed level of stability and form a hybrid
cryptocode structure (HCCS) of Niederreiter.</p>
      <p>
        In [
        <xref ref-type="bibr" rid="ref1">1</xref>
        ] the approach of unprofitable codes use in
cryptocode systems is proposed. This approach allows to build
complex cryptosystems based on the synthesis of CCC
(model of evidence-based stability) and cryptosystems on
flawed codes (multichannel cryptography). This approach
allows to reduce energy costs in the practical implementation
of CCS Niederreiter on modified (MCCC) (shortened /
extended) elliptical codes (MEC) while maintaining the
cryptographic resistance of the entire system.
      </p>
      <p>
        In [
        <xref ref-type="bibr" rid="ref2">2</xref>
        ] methods of flawed codes construction and
approaches to use of a hybrid crypto-code construction of
Niederreiter on the modified elliptical codes are considered.
      </p>
      <p>Practical algorithms for the use of the MV2 damage
mechanism in the Niederreiter crypto-code structure on
modified elliptical codes are proposed, which allows to
implement a hybrid crypto-code structure. The results of
comparative assessment of energy consumption for the
formation of an information package with different methods
of damage, which determined the choice of method of
damage in practical algorithms. The conducted research
confirms the competitiveness of the proposed cryptosystem in
Internet technologies and mobile networks, providing
practical implementation on modern platforms and the
necessary cryptographic power under post-quantum
cryptography.</p>
      <p>II.</p>
      <p>THE PRINCIPLE OF BUILDING HCCS NIEDERREITER</p>
      <p>ON FLAWED CODES</p>
      <p>The main advantage of HCCC Niederreiter is the high
speed of information conversion (relative coding speed is
close to 1). To reduce energy consumption with a guaranteed
level of safety in operation, the MCCC Niederreiter for MEC
proposed. This approach reduces the field strength and allows
to implement the classic version of the Niederreiter scheme
with a guaranteed level of stability.</p>
      <p>In the classical Niederreiter scheme, in the first stage of
cryptogram generation, the plaintext characters are converted
into error vector characters based on the equilibrium coding
algorithm. The obtained error vector in the second stage of
cryptogram generation is shortened on the basis of the code
reduction algorithm, multiplied by the check matrix of the
algebraic (elliptical) code.</p>
      <p>Copyright © 2019 for this paper by its authors. Use permitted under Creative Commons License Attribution 4.0 International (CC BY 4.0)</p>
      <p>After the formation of private key matrices, the authorized
user must form elements of a set of fixed plaintext, which are
not suitable for further formation of the cryptogram (error
vector syndrome).</p>
      <p>The theoretical basis for the construction of flawed texts is
to eliminate the order of the symbols of the source text and, as
a consequence, reduce the redundancy of language symbols in
the defective text. At the same time, the amount of
information expressing this ordering will be equal to the
decrease in the entropy of the text compared to the maximum
possible value of entropy, ie equivalent to any letter after any
previous letter. To obtain imperfect text (FTC) and damage
(DCH), the method of "perfect" compression is used after
performing m cycles of the damage mechanism Cm. The use
of the damage procedure in the CCC is possible in the
following ways:
•
•</p>
      <p>Method 1: damage to plaintext with subsequent
encryption of the losing text and/or its loss;</p>
    </sec>
    <sec id="sec-2">
      <title>Method 2: damaging the ciphertext; Method 3: damage to plaintext with subsequent encryption of unprofitable text and damage to flawed ciphertext (Fig. 1).</title>
      <p>Using the plaintext damage approach (third) from the
MCCC Niederreiter for MEC increases the bandwidth starting
from the GF field (29). This method is the best approach for
building a hybrid MCCC Niederreiter for MEC.</p>
      <p>The synthesis of Niederreiter's crypto-code structure with
a cryptosystem with flawed codes allows to build complex
(hybrid) crypto-code schemes, the stability of which is
determined by the strength of two cryptosystems to ensure the
implementation of fast cryptotransformations by reducing
field strength.</p>
      <p>III.</p>
      <p>CRYPTOGRAPHY INCRYPTION AND ENCRYPTION</p>
      <p>ALGORITHMS IN NIEDERREITER HCCS</p>
      <p>The algorithm for generating a cryptogram in a hybrid
Niederreiter CCC on MEC using flawed codes can be
represented as a sequence of steps:</p>
      <p>Step 1. Entering the information to be encoded, the
elements of a set of valid plaintext. Entering the public key
Hx.</p>
      <p>Step 2. The formation of the error vector e, the weight of
which does not exceed t, corrects the ability of the elliptical
code based on the algorithm of non-binary equilibrium
coding.</p>
      <p>i 1
K D</p>
    </sec>
    <sec id="sec-3">
      <title>Plain text M</title>
    </sec>
    <sec id="sec-4">
      <title>Damage procedure</title>
    </sec>
    <sec id="sec-5">
      <title>Damage</title>
      <p>i 1
CH D</p>
    </sec>
    <sec id="sec-6">
      <title>Damaged text</title>
      <p>CFTi1
KUi MCCC-based encryption</p>
    </sec>
    <sec id="sec-7">
      <title>Ciphertext</title>
      <p>i 2
K D</p>
    </sec>
    <sec id="sec-8">
      <title>Damage procedure</title>
    </sec>
    <sec id="sec-9">
      <title>Damage</title>
      <p>i 2
CH D</p>
    </sec>
    <sec id="sec-10">
      <title>Damaged text</title>
      <p>CFTi2
−1
 P
−1
Step 5. Removal of mixing and multiplicity matrices (5)</p>
    </sec>
    <sec id="sec-11">
      <title>Step 6. Decoding the vector c*. Getting ех.</title>
    </sec>
    <sec id="sec-12">
      <title>Step 7. Convert vector ех (6)</title>
      <p>Step 8. Formation of the error vector (7)
ex = cx  D  P
e = ex + IV2
()
()
()
()</p>
      <p>Step 9. The transformation of the vector e is based on the
use of non-binary equilibrium coding in the information
sequence.</p>
      <p>The use of a modified crypto-code construction of
Niederreiter (MCCC) with additional initialization vectors
(with set of invalid position vectors, error vector and multiple
error vector reduction positions) requires increasing the rate
of cryptographic transformation of the system as a whole. The
use of the Niederreiter MCCC on flawed codes can increase
the speed of code conversion by reducing the field strength
when causing damage to plaintext and reducing the amount of
data transmitted by damaging the ciphertext. This approach
allows to build hybrid cryptocode structures based on the
synthesis of Niederreiter modified crypto-code structures on
modified (shortened or extended) codes on elliptic curves
with damage procedures. A significant difference from
classical hybrid (complex) cryptosystems is the use of
asymmetric cryptosystems to ensure data security with fast
crypto-transformations (generation and decoding of
codograms).</p>
    </sec>
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  <back>
    <ref-list>
      <ref id="ref1">
        <mixed-citation>
          [1]
          <string-name>
            <surname>Evseev</surname>
            ,
            <given-names>S.</given-names>
          </string-name>
          ,
          <article-title>"Ispol'zovaniye ushcherbnykh kodov v kripto-kodovykh sistemakh" [Using flawed codes in crypto-code systems</article-title>
          ] // SOI . -
          <year>2017</year>
          . - №
          <volume>5</volume>
          (
          <issue>151</issue>
          ). P.
          <volume>109</volume>
          -
          <fpage>121</fpage>
          . https://doi.org/10.30748/soi.
          <year>2017</year>
          .
          <volume>151</volume>
          .15.
        </mixed-citation>
      </ref>
      <ref id="ref2">
        <mixed-citation>
          [2]
          <string-name>
            <surname>Yevseiev</surname>
            ,
            <given-names>S.</given-names>
          </string-name>
          <article-title>Development of Niederreiter hybrid crypto-code structure on flawed codes / Serhii Yevseiev</article-title>
          , Oleksii Tsyhanenko, Alla Gavrilova, Viktor Guzhva, Oleksandr Milov, Valentina Moskalenko, Ivan Opirskyy, Oleksandr Roma, Bogdan Tomashevsky, Olexander Shmatko // Eastern-European
          <source>Journal of Enterprise Technologies. - 2019</source>
          . - Vol. 1,
          <string-name>
            <surname>N</surname>
          </string-name>
          <volume>9</volume>
          (
          <issue>97</issue>
          ). - P.
          <fpage>27</fpage>
          -
          <lpage>38</lpage>
          . - Way of Access : DOI : 10.15587/
          <fpage>1729</fpage>
          -
          <lpage>4061</lpage>
          .
          <year>2019</year>
          .
          <volume>156620</volume>
          .
        </mixed-citation>
      </ref>
      <ref id="ref3">
        <mixed-citation>
          [3]
          <string-name>
            <surname>Mishchenko</surname>
            ,
            <given-names>V.A.</given-names>
          </string-name>
          and
          <string-name>
            <surname>Vilansky</surname>
          </string-name>
          ,
          <string-name>
            <surname>Yu</surname>
          </string-name>
          .V. (
          <year>2007</year>
          ), “
          <article-title>Ushherbnye teksty i mnogokanal'naja kriptografija” [Damage texts</article-title>
          and multichannel cryptography], Encyclopedic, Minsk, 292 p.
        </mixed-citation>
      </ref>
    </ref-list>
  </back>
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