polyalphabetic substitution

An environment in which one knows he or she must constantly maintain precautions is safer than one where they are unaware of the dangers that potentially exist.

This concept is exemplified in the case of Mary Queen of Scots by the simple fact that her naive belief that she was speaking in secrecy directly resulted in her death. She essentially signed up for her own funeral by openly disclosing matters of treason. If she had been living in the era in which it was common knowledge that a “codebreaker might intercept and decipher their most precious secrets,” (Singh, p.45) then it is much more likely she would have been less forthcoming with the information she provided in her encrypted messages.

The new environment created was far more advanced than anyone in her time could have predicted. Mary’s generation falls in the era of monoalphabetic substitution, whereas the new age moved on to as many as twenty-six (polyalphabetic). Furthermore, everyone in this new era of cryptography frequently changed their methods. They would not be caught dead using such a basic cipher over a prolonged period of time to transport such crucial information. Even the ciphers used for general business information transported by telegraphs was more secure than the cipher Mary trusted her life with.

The new environment of encryption even allowed for progression in the cryptography field. As ciphers became more complex, more professional codebreakers emerged that continued to prove how difficult it was to create an uncrackable code. In turn, this generated more ciphers and the loop continues from there. Progression did not just make the population more cautious, but it also generated societal growth.

Encryption Strengthens as Human Technology Improves

By floreaa

On September 18, 2018

In Student Posts

By the mid 19th century, the skills and techniques used to break simple monoalphabetic substitution ciphers or keyword ciphers were well known between coder breakers. Tools such as frequency analysis were vital to decoding messages, encrypted messages intercepted through Morse code had no chance of staying secure. Messages needed to be encrypted with a stronger mechanism such as a polyalphabetic substitution cipher that could render a normal frequency analysis obsolete.

My first thought of modern communication that required a major change to keep our communication secure was email. Primitive computer messaging had little to no security, and once there was a realization that digital messaging would become popular, the communication programs had to be equipped with the tools that could keep each user’s data safe. These encryption processes had to be security enough to withstand the code breaking technologies now. For this reason stronger encryption systems such AES 3DES have been developed to maintain the user’s data safe. The algorithms we have developed turn any piece of user inputted data such as a password, message, or personal information into a string of characters and send that string through numerous systems until the data reaches whatever the intended recipient is. In way we have created two types of communication, one in which humans communicate with technology and second where one piece of technology communications with another. It is interesting to think about all our modern communication like this because we cannot see the latter form. We cannot also know what happens to our data in route to the receiver, that is why sometimes we take precautions that hopefully secure our data and maintain our privacy. Other times we take risks and our private data can be accessed through some third party technology.

200 Years of Strength

By youngar

On September 20, 2017

In Student Posts

The first thing The Great Cipher used by Louis XIV did well was not being a monoalphabetic cipher. These ciphers are too susceptible to frequency analysis, making them crackable in a matter of hours at the most. Instead, the Great Cipher is more along the lines of a polyalphabetic cipher. Instead of letters, however, the cipher alphabets are compromised of numbers. But the thing that really makes this cipher a strong one is the fact that these numbers represent single syllables, letters, or even commands instead of just single letters. In doing this, deciphering The Great Cipher would take years.

This cipher took 200 years to decipher due to the odd nature of the cipher. No conventional ciphers substituted numbers for both syllables and letters, as well as having some traps lain within. Due to this, nobody knew how to begin deciphering it. It was only through the efforts of Bazeries that this cipher was eventually cracked. Even so, it took Bazeries 3 whole years to figure out the messages hidden behind the code. He was only able to crack the code as a result of his very out of the box thinking and pure determination. After trying polyalphabetic combinations, which are hard enough to crack on their own due to the pure number of possibilities that exist, and diagraphs, which also took a long time, Bazeries thought to try syllables. It was only after trying many different combinations that he found a single phrase which worked. He then used this word to painstakingly decipher the rest of the text. The pure creativeness of The Great Cipher led to its strength, and the only way it could be decoded was through equal creativity.

The Smithy Code: A Look Into Multiple Encryption

By gundamy

On October 8, 2015

In Student Posts

On Elonka’s website, there is an explanation and solution to the Smithy Code. The Smithy Code was embedded in the ruling for a plagiarism trial concerning Dan Brown’s The Da Vinci Code. Justice Peter Smith italicized several letters which spelled out “S m i t h y c o d e J a e i e x t o s t g p s a c g r e a m q w f k a d p m q z v -” — “Smithy code” is in English, and the rest is ciphertext which evidently involves a polyalphabetic substitution cipher. According to the explanation, Smith used a series of Caesar shifts based on the letters that correspond to the numbers of the Fibonacci sequence. Usually, this would be 1-1-2-3-…, which would correspond to A-A-B-C-…. However, Smith added a twist and replaced the letter B with the letter Y. He then used a grid of the Caesar shifts and found the plaintext letter in the grid, then traced it up to the letter at the top of the column to encipher it, similar to the way one would decode a Vigenère cipher.

In class, we have discussed Caesar ciphers, polyalphabetic substitution ciphers, and the Vigenère cipher (a type of polyalphabetic cipher). The Smithy Code was an intricate interweaving of all of these methods and a method inspired by The Da Vinci Code (the Fibonacci Sequence), because of the novel’s relevance to the trial. It was a fascinating look into a method by which several ciphers can be used, and how far common knowledge and research about cryptography has come in order for these methods to be implemented.

Cryptography

The History and Mathematics of Codes and Code Breaking

Tag: polyalphabetic substitution

Uncertain Environments Generate Safer Practices

Encryption Strengthens as Human Technology Improves

200 Years of Strength

The Smithy Code: A Look Into Multiple Encryption

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