Commit c8508db

soxfox42Panquesito7vbrazo

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Update Playfair explanation (#191)

* Fix Playfair example matrices * Change Playfair filler letter to X This matches the Python implementation, the video linked on the page, and most documentation of the Playfair cipher. * Clarify duplicate pairs in Playfair I think this wording is a little clearer when it comes to how double letter digraphs should be handled. Co-authored-by: David Leal <halfpacho@gmail.com> Co-authored-by: Vitor Oliveira <vbrazo@gmail.com>

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`‎en/Ciphers/playfair-cipher.md‎`

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Original file line number	Diff line number	Diff line change
`@@ -53,21 +53,21 @@ The rules above are used for Encryption. Can be applied vice-versa for Decryptio`
`53`	`53`	```
`54`	`54`	`[m o n a r]`
`55`	`55`	`[c h y b d]`
`56`		`- [e f g k i]`
	`56`	`+ [e f g i k]`
`57`	`57`	`[l p q s t]`
`58`	`58`	`[u v w x z]`
`59`	`59`	```
`60`	`60`
`61`		`-2. Split the plaintext in digraphs(pair of two). If there is an odd number of letters, a Z is added to the last letter. Pair cannot be made with same letter. Break the letter in single and add a bogus letter to the previous letter.`
	`61`	`+2. Split the plaintext in digraphs(pair of two). If there is an odd number of letters, an X is added to the last letter. Pairs cannot be made with same letter. If this occurs, split the pair by adding an X between the duplicate letters.`
`62`	`62`
`63`	`63`	```
`64`		`- 'in' 'st' 'ru' 'me' 'nt' 'sz'`
	`64`	`+ 'in' 'st' 'ru' 'me' 'nt' 'sx'`
`65`	`65`	```
`66`	`66`
`67`	`67`	`3. Now, we need to follow the rules for encrypting and do as follows:`
`68`	`68`
`69`	`69`	```
`70`		`- Plain Text: instrumentsz`
	`70`	`+ Plain Text: instrumentsx`
`71`	`71`	`key: monarchy`
`72`	`72`	`Encryption:`
`73`	`73`	`i -> g`
`@@ -80,10 +80,10 @@ The rules above are used for Encryption. Can be applied vice-versa for Decryptio`
`80`	`80`	`e -> l`
`81`	`81`	`n -> r`
`82`	`82`	`t -> q`
`83`		`- s -> t`
`84`		`- z -> x`
	`83`	`+ s -> x`
	`84`	`+ x -> a`
`85`	`85`	```
`86`		`-So we will get the encrypted text as gatlmzclrqtx.`
	`86`	`+So we will get the encrypted text as gatlmzclrqxa.`
`87`	`87`
`88`	`88`	`### Decryption`
`89`	`89`
`@@ -92,17 +92,17 @@ So we will get the encrypted text as gatlmzclrqtx.`
`92`	`92`	```
`93`	`93`	`[m o n a r]`
`94`	`94`	`[c h y b d]`
`95`		`- [e f g k i]`
	`95`	`+ [e f g i k]`
`96`	`96`	`[l p q s t]`
`97`	`97`	`[u v w x z]`
`98`	`98`	```
`99`	`99`
`100`	`100`	`2. We need to split the ciphertext as done for plaintext while encrypting`
`101`	`101`	```
`102`		`- 'ga' 'tl' 'mz' 'cl' 'rq' 'tx'`
	`102`	`+ 'ga' 'tl' 'mz' 'cl' 'rq' 'xa'`
`103`	`103`	```
`104`	`104`
`105`		`-3. For the previous Cipher Text gatlmzclrqtx, by following the rules we get:`
	`105`	`+3. For the previous Cipher Text gatlmzclrqxa, by following the rules we get:`
`106`	`106`
`107`	`107`	```
`108`	`108`	`Plain Text: gatlmzclrqtx`
`@@ -113,9 +113,9 @@ So we will get the encrypted text as gatlmzclrqtx.`
`113`	`113`	`mz -> ru`
`114`	`114`	`cl -> me`
`115`	`115`	`rq -> nt`
`116`		`- tx -> sz`
	`116`	`+ xa -> sx`
`117`	`117`	```
`118`		`-So we will get the encrypted text as instrumentsz.`
	`118`	`+So we will get the encrypted text as instrumentsx.`
`119`	`119`
`120`	`120`	`## Implementations`
`121`	`121`

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