EsoCipher: An Instance of Hybrid Cryptography

Abstract

This paper proposes a whole new concept in the field of Cryptography , i.e., EsoCiphers. Short for Esoteric Cipher, EsoCipher is an algorithm, which can be understood by a few, who have the knowledge about its backend architecture. The idea behind this concept is derived from esoteric programming languages, but EsoCiphers will be having a practical use in the future, as more research is done on the topic. Although the algorithm is quite simple to understand, the complexity of the output will indeed prove to be difficult to bruteforce if a secret is embedded to it. It uses a hybrid cryptography based technique, which combines ASCII, Binary, Octal and ROT 13 ciphers. The implementation and similarity index has been provided to show that it can be implemented practically.

Full text

EsoCipher: An Instance of Hybrid Cryptography
Neel Adwani
University of Petroleum and Energy Studies
Dehradun, Uttarakhand
contact@neeltron.com
ABSTRACT
This paper proposes a whole new concept in the eld of Cryptog-
raphy, i.e., EsoCiphers. Short for Esoteric Cipher, EsoCipher is an
algorithm, which can be understood by a few, who have the knowl-
edge about its backend architecture. The idea behind this concept
is derived from esoteric programming languages, but EsoCiphers
will be having a practical use in the future, as more research is done
on the topic. Although the algorithm is quite simple to understand,
the complexity of the output will indeed prove to be dicult to
bruteforce if a secret is embedded to it. It uses a hybrid cryptog-
raphy based technique, which combines ASCII, Binary, Octal and
ROT 13 ciphers. The implementation and similarity index has been
provided to show that it can be implemented practically.
1 INTRODUCTION
According to the international standards, the term "esoteric" is
dened as something that can be understood by a small group of
people, having knowledge of the same. A common term, similar to
it is "esolang", short for esoteric programming language [
10
] which
can be further stated as a language that can be decoded by some
specic compilers or interpreters. One such example of an esoteric
programming language is Malbolge [
7
]. As for Esoteric Cipher, it
is not entirely an esoteric language, nor an ordinary cipher, but a
mixture of both of them, making it entirely a hybrid cryptographic
technique [1].
In Layman terms, cryptography is a study of dierent techniques,
in order to protect data or any sort of communications happening
through any medium. A Cipher would be dened as an algorithm
that can encrypt or decrypt the data.
In our case, the algorithm is totally dependent upon communica-
tion of text based messages, and the key to it will be as per the user’s
preference. Initially, the user will have to type the message, and
then the secret. The secret will be embedded to the message, which
is similar to salting but not exactly the same. Upon execution of the
algorithm, it’ll translate the message into an entirely tangled string,
which would be almost impossible to decipher without having the
secret.
* The terms key and secret can be used interchangeably, within
the scope of this paper.
2 RELATED WORK
This section demonstrates a glimpse of related algorithms that have
been implemented and are currently in use.
Malbolge [
7
] is an esoteric programming language, which uses
characters based on the ASCII table and has a specied range of
printable and non-printable characters, depending upon that range.
Instead of Deciphering algorithms, esoteric languages have inter-
preters and they’re mostly proposed as jokes. Another popular
esoteric language is Brainfuck [
5
], which became notable for its
minimalistic expressions. The whole language constitutes 8 simple
commands and an instruction pointer. LOLCODE [
8
] is yet another
esoteric language, which is based on the lolcat meme. So, its les
are generated of the extensions .lol and .lols. Since its inspiration
comes from memes over the internet, the syntax contains keywords
like HAI, BTW, GTFO, KTHXBYE.
While there’s no intended practical use of esoteric languages, Es-
oCipher may be considered obfuscated but it can be proven useful in
some elds. Since a lot of exploration hasn’t been done around this
topic, it is hard to determine the usability of the given algorithms in
this paper, but intentionally EsoCiphers can be useful in preventing
the attacker from reading the data during data breaches. It can
even be used in Machine Learning/Deep Learning Models where
sensitive data is required to train the model. No human will be able
to make sense out of that data, without knowing the key and the
exact functions used in their algorithm. On another note, the given
algorithms can be modied, depending upon the requirements of
the developer.
3 ALGORITHMIC AND PROCEDURAL
BACKGROUND
This section presents the back-end of this algorithm, which provides
a good idea about its working approach and the ways it can be
implemented in dierent languages.
3.1 Encipher
During the process of enciphering, the algorithm initially replaces
special characters like ’.’, ’,’, ’@’, ’!’, etc., with their alphabetical
counterparts like "period", "comma", "at", "exclamation", which are
absolutely exible, making the cipher exible and secure, as per
the special characters are dened. Moving forward, the ASCII [
3
]
value of each alphabet is converted into binary and then embedded
into a new variable as a string. The character ’b’ has to be removed
as it may cause conversion errors. After that, the octal [
6
] value
of that string is taken into account for an integer of the whole
string and nally, the ROT13 [
4
] Algorithm is executed and the
enciphered string executed by the EsoCipher Algorithm is obtained.
A summarized visualization for the same is shown in Fig. 1.
3.2 Decipher
In order to decipher the EsoCipher, the program needs an "EsoCi-
phered" string to begin with. After the successful input of the string,
it is looped through and a ROT -13 is executed on it, i.e., the ASCII
value of each character is decreased by 13 and stored collectively in
a variable. For each group of 8 characters, a 0 is added initially and
then an octal value is received. The octal value is then taken into
account and converted to binary. For each series of 8, the binary

Neel Adwani
Algorithm 1: Generating an EsoCipher
Result: The EsoCipher is returned as a string.
input_string = "", modied_string = "", iter = 0, x = 0,
temp_string = "";
𝑖𝑛𝑝𝑢𝑡 _𝑠𝑡𝑟 𝑖𝑛𝑔 ←”𝑆𝑎𝑚𝑝𝑙𝑒𝑆 𝑡𝑟𝑖𝑛𝑔”;
while iter < len(input_string) do
𝑥←𝑏𝑖𝑛𝑎𝑟𝑦(𝑎𝑠𝑐𝑖 𝑖 (𝑖𝑛𝑝𝑢𝑡 _𝑠𝑡𝑟𝑖𝑛𝑔[𝑖𝑡𝑒𝑟] ));
𝑚𝑜𝑑𝑖 𝑓 𝑖𝑒 𝑑_𝑠𝑡𝑟𝑖𝑛𝑔 ←𝑚𝑜𝑑𝑖 𝑓 𝑖 𝑒𝑑_𝑠𝑡 𝑟𝑖𝑛𝑔 +𝑠𝑡 𝑟𝑖𝑛𝑔(𝑥);
end
𝑚𝑜𝑑𝑖 𝑓 𝑖𝑒 𝑑_𝑠𝑡𝑟𝑖𝑛𝑔 ←𝑚𝑜𝑑𝑖 𝑓 𝑖 𝑒𝑑_𝑠𝑡 𝑟𝑖 𝑛𝑔.𝑟𝑒 𝑝𝑙𝑎𝑐 𝑒 (′𝑏′,1);
𝑡𝑒𝑚𝑝 _𝑠𝑡𝑟𝑖𝑛𝑔 ←𝑜𝑐𝑡𝑎𝑙 (𝑖𝑛𝑡 (𝑚𝑜𝑑 𝑖 𝑓 𝑖𝑒 𝑑_𝑠𝑡𝑟𝑖𝑛𝑔)) ;
modied_string = "";
iter = 0;
while iter < len(temp_string) do
𝑥←𝑎𝑠𝑐𝑖𝑖 (𝑡 𝑒𝑚𝑝_𝑠𝑡𝑟𝑖𝑛𝑔[𝑖𝑡 𝑒𝑟]);
𝑥←𝑥+13;
𝑚𝑜𝑑𝑖 𝑓 𝑖𝑒 𝑑_𝑠𝑡𝑟𝑖𝑛𝑔 ←𝑚𝑜𝑑𝑖 𝑓 𝑖 𝑒𝑑_𝑠𝑡 𝑟𝑖𝑛𝑔 +𝑎𝑙𝑝ℎ𝑎(𝑥);
end
return modied_string;
Figure 1: Flowchart for understanding the Esocipher
is converted into ASCII and then the respective value of ASCII is
replaced by the corresponding alphabet, as per the given table 1. For
connotations like "period", "comma", "at", "exclamation", etc., they’re
nally converted into symbols like ’.’, ’,’, ’@’, ’!’, etc., to ensure that
the complete original string is obtained. The similarity index and
losses for the same are discussed in section 5. The algorithm for
deciphering an EsoCipher can be referred as dEsoCipher Algorithm.
A summarized visualization for the same is shown in Figure 2.
Algorithm 2: Deciphering the EsoCipher string
Result: The EsoCipher is deciphered and returned as a
string.
esocipher = "", deciphered_string = "", iter = 0, x = 0,
temp_string = "";
while iter < len(esocipher) do
𝑥←𝑎𝑠𝑐𝑖𝑖 (𝑒 𝑠𝑜𝑐𝑖𝑝 ℎ𝑒𝑟 [𝑖𝑡𝑒𝑟 ]) ;
𝑥←𝑥−13;
𝑑𝑒𝑐𝑖𝑝ℎ𝑒𝑟𝑒𝑑_𝑠𝑡𝑟 𝑖𝑛𝑔 ←𝑑𝑒𝑐𝑖𝑝ℎ𝑒𝑟 𝑒𝑑 _𝑠𝑡 𝑟𝑖𝑛𝑔 +𝑐ℎ𝑎𝑟 (𝑥);
end
𝑑𝑒𝑐𝑖𝑝ℎ𝑒𝑟𝑒𝑑_𝑠𝑡𝑟 𝑖𝑛𝑔 ←′
0
′+𝑠𝑡𝑟𝑖𝑛𝑔(𝑖 𝑛𝑡 (𝑑𝑒𝑐𝑖𝑝ℎ𝑒𝑟 𝑒𝑑 _𝑠𝑡𝑟𝑖𝑛𝑔,
8
)
;
𝑡𝑒𝑚𝑝 _𝑠𝑡𝑟𝑖𝑛𝑔 ←𝑜𝑐𝑡 𝑎𝑙 (𝑖𝑛𝑡 (𝑚𝑜𝑑𝑖 𝑓 𝑖𝑒 𝑑_𝑠𝑡𝑟𝑖𝑛𝑔)) ;
for iter in modified_string[::8] do
nal_string = nal_string + char(iter);
end
return modied_string;
4 IMPLEMENTATION OF ESOCIPHER
This section demonstrates an in-depth explanation of the way this
algorithm was implemented in Python 3.7 and it includes relevant
screenshots attached to it.
For the enciphering algorithm, no external libraries are needed
to be imported, unless a dierent cryptic function has to be used.
As for the algorithm, the users are allowed to set their own codes
to punctuation marks, so basically for more number of punctuation
marks, the cipher will get stronger. A string "hello world" is supplied
as an input to our program, with the notation for ’ ’ as "space_bar".
The output turned out to be as shown in Figure 3.
For Deciphering of the same generated string in Figure 3, a
separate algorithm was programmed in the same development
environment, as per Algorithm 2, stated above in this paper. The
string that is supposed to be inputted is the one generated in Figure
3. For looking into the results, refer to Figure 4.
5 SIMILARITY INDEX AND LOSSES
This section is about testing Algorithm 1 on a random paragraph,
Algorithm 2 on the result generated from Algorithm 1, and calcu-
lating the Levenshtein Distance [
2
] [
9
] between the original string
(random paragraph) and the output of Algorithm 2. Since the punc-
tuation marks are to be dened by the user, it is assumed within the
scope of this paper, that all the punctuation marks in the paragraph
are annotated in both the algorithms.
A short excerpt from a Harry Potter novel is taken, which went
through both the algorithms and the Levenshtein distance between

EsoCipher: An Instance of Hybrid Cryptography
Figure 2: Flowchart for understanding the process of deci-
phering an Esocipher
Figure 3: Output during Enciphering
Figure 4: Output during Deciphering
the original string and the deciphered string turns out to be 1, which
is due to a punctuation error, and is solvable with some alterations.
Refer to Figure 5 for the implementation.
Since the Levenshtein distance is 1 in a string of 234 characters,
the loss turns out to be 0.427%, which will be considerably lower
Figure 5: Implementation of Levenshtein’s Distance Algo-
rithm
and even 0 if all the punctuation marks are dened correctly in the
source code.
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