Cryptography Techniques: Substitution Cipher, Commercial and Export

This discussion assignment explores the realm of cryptographic techniques, specifically focusing on substitution ciphers. The assignment delves into the methods used to break these ciphers, such as analyzing letter frequencies and identifying patterns, as well as designing secure ciphers based on substitution techniques. It examines the application of cryptography in the commercial world, highlighting the increasing need for data security and the role of cryptography in protecting sensitive information. Furthermore, the assignment addresses the complexities of export control on cryptographic techniques, considering the balance between national security and the global demand for secure data transmission. The assignment concludes by referencing relevant literature and research in the field of cryptography.

Running head: CRYPTOGRAPHIC TECHNIQUES
SUBSTITUTION CIPHER AND CRYTOGRAPHY TECHNIQUE
[Enter Name of Student:]
[Enter Name of University:]
[Author Note:]

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Week1 discussion 1:
Techniques to break the substitute cipher –
Cryptography is the study and analysis of encoded texts and messages using various
techniques and algorithms. Substitution technique in the cryptography is one of the several
techniques to encode a text. Substitution cipher can be termed as the process of encrypting a
single text or message and replacing the text with cipher text (Katz and Lindell 2014). Caesar
cipher is an example of the substitution cipher where the alphabets are substituted either by
shifting the sequence or by reversing the sequence with the cipher texts. These substitution
ciphers can be decoded by the process of continuous search of single letter words and also
counting of the each symbols appearing in the puzzle should be counted. The symbols such as
apostrophes should be looked after and in the encoded message segment such apostrophes must
be found out. The cipher text also contains certain repetitive letters which helps in the decoding
of the cipher blocks which contains two or three words at a time (Goyal and Kinger 2013). The
double letters in the cipher text is also to be followed and these techniques combined together
helps in the breaking of substitution ciphers. The black chamber is also an application which can
be used as a predefined platform for decoding or breaking a substitution cipher.
Secure cipher design using substitution ciphers –
The designing of cipher using substitution ciphers is done by the application of several
techniques of forward and reverse substitution of the cipher blocks. The cipher texts are mainly
plain texts which are encoded using algorithms into cipher texts which are considered to be
secure ciphers as because certain keys are required in order to break or decode the cipher texts to
get the plain text. The substitution method can be termed a secured as because the retracing of

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the plain text from the cipher text is very difficult (Hauer, Hayward and Kondrak 2014). The
algorithm used for the process also ensures that the cipher blocks are not repetitive and any
random letter can be substituted in the cipher text and thus the retracing process can be very
much difficult. The substitution cipher is designed to be secure in terms of encoding and
decoding as because the reverse process of decoding is difficult due to the presence of unknown
pattern of substituted letters. Thus using the substitution cipher method, secure cipher can be
generated and used.
Week1 discussion 2:
Should cryptography be restricted in commercial world –
In the commercial world, the need of cryptography is increasing with the increase in the
number of internet attacks against important credentials of the users. The users can use
cryptography in order to secure the data and thus prevent any intrusion. The commercial world
includes many threats of the attackers and many important credential data of the user as well as
company are exposed and thus cryptography needs to be applied in the field of commercial
world (Kahate 2013). The cryptography deals with the encryption of such data using various
techniques of public and private keys and the resultant cipher texts can be decode by either the
user or the company using private keys. The cryptographic techniques were generally used by
the governments and military in the earlier years but however the technique should be adapted by
the commercial world as well in order to maintain the security and integrity of the user’s data.
Export control on cryptographic techniques –
Certain restriction existed in the export of cryptographic techniques earlier however, the
export was initiated later on in various countries. The advance weapon that are developed by

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various countries in order to defend them should not be exported in order to maintain peace and
harmony over the world as these advance weapons are usually mass destructive ones. The
commercial world includes many threats of the attackers and many important credential data of
the user as well as company are exposed and thus cryptography needs to be applied in the field of
commercial world (Anand, Khemchandani and Sharma 2013). However, the export of
cryptographic techniques can be done in various countries where the users demand security for
the transmission of data. The export control on cryptographic techniques should be levied as it
exists in advanced weapon control, in order to control the security purpose of the data (Tripathi
and Agrawal 2014). The export of advanced weapons are done in terms of government laws and
regulations and in case of cryptography technique export, certain laws and regulations must be
maintained such as the techniques should only be delivered to company officials and no
individual should get such access, as because, the breaking of the cryptographic process will the
get easy and thus the process would be vulnerable.

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References
Anand, D., Khemchandani, V. and Sharma, R.K., 2013, September. Identity-based cryptography
techniques and applications (a review). In 2013 5th International Conference and Computational
Intelligence and Communication Networks (pp. 343-348). IEEE.
Goyal, K. and Kinger, S., 2013. Modified Caesar Cipher for Better Security Enhancement.
International Journal of Computer Applications, 73(3), pp.27-31.
Hauer, B., Hayward, R. and Kondrak, G., 2014, August. Solving substitution ciphers with
combined language models. In Proceedings of COLING 2014, the 25th International Conference
on Computational Linguistics: Technical Papers (pp. 2314-2325).
Kahate, A., 2013. Cryptography and network security. Tata McGraw-Hill Education.
Katz, J. and Lindell, Y., 2014. Introduction to modern cryptography. Chapman and Hall/CRC.
Tripathi, R. and Agrawal, S., 2014. Comparative study of symmetric and asymmetric
cryptography techniques. International Journal of Advance Foundation and Research in
Computer (IJAFRC), 1(6), pp.68-76.