Three kind of cryptographic: Commentary
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Three kind of cryptographic: Commentary


I write about three kinds of ciphers, acrostic, Substitution cipher, and anagram. Cryptography refers to information written so that its true intention is conveyed only to a specific person.

During war, the document was encrypted so that the strategy would not be conveyed to the enemy. In a broader sense, it is also used as rhetoric for entertainment such as songs and novels. In the novel, there is a technique is devised so that multiple interpretation.



-Contents-
・Words hidden in Iroha uta
・Julius Caesar’s cipher
・Anagram and Harry Potter



Three kind of cryptographic

Words hidden in Iroha uta


"Acrostic" is famous as cipher. Acrostic is a technique to convey the trueness of hidden sentences. When readers select some words in a sentence, another sentence emerges.

 Famous example is a letter addressed to Congress by Governor Arnold Alois Schwarzenegger. In japan, Iroha uta is used Acrostic in this poem. Iroha uta is a sentence that arranged 47 hiragana characters so as not to use twice. Iroha uta is posted below.


いろはにほへと ちりぬるを
わかよたれそ  つねならむ
うゐのおくやま けふこえて
あさきゆめみし ゑひもせす


(Beautiful color flowers will someday wither. There is no unchangeable thing in this world. I don’t dream or leave it to drunk transcending this world)

When you separate Iroha uta every seven letters, you will see something like this.


いろはにほへ
ちりぬるをわ
よたれそつね
らむうゐのお
やまけふこえ
あさきゆめみ 
ゑひもせ 


When extracting the rightmost letter of each line, the sentence "とかなくてしす", that is, "I will die with innocence" emerges.

Although the author of Iroha uta is still unknown, there is a theory that it is a poem that someone who is executed with innocent sin wrote. By extracting characters based on specific rules like this, we can find different meanings in the sentences.


Julius Caesar’s cipher


The cipher used by Julius Caesar is called substitution cipher. Caesar encrypted the document so that information would not be leaked when a message was received by enemy soldiers during wartime. Way to solve the Caesar's cipher is to shift each alphabet by some number. 

Shifting rule (shifting number, shift to the front or back), were instructed to the other message commander apart from the document carriers. Although it is a simple cryptogram, the epoch-making point of Caesar is that preparing a key to solve cryptography (a rule for solving ciphers) with separating from letter. The way to prepare the key for the document and share the key with the other party by another method is the basis of all current information communication.


Anagram and Harry Potter


Anagram is famous cipher too. Anagram is a kind of word play that creates different sentences and words by rearranging the letters of the name. Unlike the above two, since there can be countless numbers of sentences by changing the order of letters, it is not suitable for cryptography for confidential documents during wartime. 

Anagram has been incorporated into many literary works. In J. K. Rowling 's work "Harry Potter", there is a setting that name 'Tom Marvolo Riddle' can be seen 'I am Lord Voldemort' when rearranging the letters . Dan Brown's work "Digital Fortress" uses the anagram that is the key to the story. In the work of Japan, Haruki Murakami makes character Makimura hiraku in "Dance · Dance · Dance", as an anagram of his own name.

As a digression story, in Harry Potter, there are many cases where the name of the character represents its personality. For example, Severus Snape is a combination of English and Latin which means it is cruel and harsh. Malfoy is depicted as a symbol of "unreliable person" by combining foi meaning trust with prefix mal which means bad.