Analysis of Cryptography: Confidentiality and One-Time Pad Encryption

This report delves into the analysis of cryptography, focusing on the core objectives of modern cryptography: confidentiality, integrity, non-repudiation, and authentication. It then provides a detailed description of the one-time pad encryption method, a technique known for its theoretical uncrackability when implemented correctly. The report explains the process of encryption and decryption using this method, including a numerical example to illustrate how plaintext is transformed into ciphertext using a secret key. The report highlights the crucial strategies required to ensure the security of the one-time pad encryption, such as the randomness and secrecy of the key. Finally, it underscores the importance of the encryption technique in securing confidential information. The report also includes references to relevant literature on the topic.

Running head: ANALYSIS OF CRYPTOGRAPHY
ANALYSIS OF CRYPTOGRAPHY
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1ANALYSIS OF CRYPTOGRAPHY
Introduction
Cryptography is a process of securing information and communication through applications
of codes. Only people who are involved in information sharing have access to these codes
which is required to process information and therefore capable of retrieving insight from this
information (Stinson & Paterson, 2018). This is a popular method for sharing information
that are confidential in nature and it ensure that only people who are authorized to access this
information are capable of deciding this encrypted information. There are various methods
for encrypting information and how information is encrypted and decrypted depends on a
specific cryptographic system. However, no matter which cryptographic system is applied for
encrypting information, the purpose is same which is to enhance security of information by
ensuring that it is not easy to retrieve information from encrypted data.
In modern cryptography, there are four objectives that need to be considered and these
objectives are the followings:
Confidentiality:
After information is encrypted, it should not be easy to decrypt that information by people
who are not meant to access that information (Goldreich, 2019). Therefore, ensuing
confidentiality is one of the most important aspects of cryptography.
Integrity:
After information encrypted by sender and then it is decrypted by a receiver, there should not
be any loss of information and originality of the information needs to be ensured therefore,
ensuring integrity of the information (Goldreich, 2019).

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Non-repudiation:
The creator or sender who encrypt the information and send it to a receiver should not deny
intention for creating or sending that information at any stage of this process (Kraft &
Washington, 2018).
Authentication:
Sender and receiver of information should be capable of confirming their identity along with
source and destination of information for ensuring authenticity as well (Kraft & Washington,
2018).
Description of cryptographic system
The cryptographic system that is considered in this context is one-time pad encryption. This
is an encryption technique which is not possible to crack. However, to decrypt this
information, it is required to apply a one-time key that is pre-shared by the creator who has
encrypted the information (Li et al., 2017). One important thing to note in this context is this
pre-shared key needs to be of same size of message or it might be longer than size of the
message as well. In this encryption technique, first a plain text needs to be paired for this a
random key only known to creator is applied. This secret key is known as one-time pad and
therefore, this encryption technique is known as one-time pad encryption.
Each bit or character contained in plain text needs to encrypted and then it is combined with
respective bit or character of the pad through application of modular addition. In order to
ensure that chipper text obtained by applying this encryption method is impossible to decrypt
for anyone not authorized to access this system then it is important to consider some
strategies and these strategies are the following (Rahim et al., 2018):
 The key that is considered for encryption has to be totally random

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 The key has to be minimum as long as the size of the plain text on which encryption is
being applied
 The key is never applied neither in parts nor in whole in any other encryption
 The key has to be kept secret and it is accessed by anyone rather than creator of the
encryption
If all of these aspects are properly ensured while applying this encryption method, then it is
impossible to decrypt that encrypted plaintext if authorization is not provided by the creator
of the encrypted information.
In this context, an example is provided for a comprehensive overview regarding how a plain
text is encrypted and how it is decrypted as well.
Plaintext M E E T M E O U T S I D E
Numerical
plaintext
12 4 4 19 12 4 14 20 19 18 8 3 4
OTP B D U F G H W E I U F G W
Numerical
OTP
1 3 2
0
5 6 7 22 4 8 20 5 6 22
Numerical
Ciphertext
13 7 2
4
24 18 11 10 24 1 12 13 9 0
Ciphertext N H Y Y S L K Y B M N J A
Therefore, the ciphertext is “NHYYSLKYBMNJA”.
It is identified from the analysis that if access to that one-time pad encryption key is not
ensured, then it is not possible to decrypt the plain text and therefore, it enhances security of

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information. It is a preferred method for encrypting confidential information it is capable of
ensuring that information is not easy to access and for that access to decryption key is
required and therefore it is an effective encryption technique as well.

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References:
Goldreich, O. (2019). On the foundations of cryptography. In Providing Sound Foundations
for Cryptography: On the Work of Shafi Goldwasser and Silvio Micali (pp. 411-496).
Kraft, J., & Washington, L. (2018). An introduction to number theory with cryptography.
CRC Press.
Li, J., Xiong, J., Zhang, Q., Zhong, L., Zhou, Y., Li, J., & Lu, X. (2017). A one-time pad
encryption method combining full-phase image encryption and hiding. Journal of
Optics, 19(8), 085701.
Rahim, R., Kurniasih, N., Mustamam, M., Andriany, L., Nasution, U., & Mu, A. H. (2018).
Combination Vigenere Cipher and One Time Pad for Data Security. Int. J. Eng.
Technol, 7(2.3), 92-94.
Stinson, D. R., & Paterson, M. (2018). Cryptography: theory and practice. CRC press.