Using PHP$,$ HTML$,$ Javascript, CSS$,$ and SQL$.$

Your web application lets the users encrypt and decrypt texts in input $($from an input box or a file$).$ The user can select from a list of ciphers and specify if it needs encryption or decryption.

$-$It would be very cool to implement a logic able to detect the cipher used to encrypt a text in input, without let the user specify it $($this would make the project "Incredibly Intense", though$).$

You will have to:

Build a web page that:

$-$Ensures a secure Session mechanism.

$-$Allows the user to sign up and log in$.$

$-$Allows the user to submit a text file $($extension $.$txt ONLY$).$

$-$Allows the user to submit text in an input text box.

$-$Allows the user to select a cipher from a list and if the input should be encrypted or decrypted.

Build a web application that:

$-$Reads the file in input and the cipher selected, then applies this cipher $($encryption or decryption, based on the user's input$).$

$-$Reads the text from the input text box, if any, and the cipher selected, then applies this cipher $($encryption or decryption, based on the user's input$)$

$-$Implements these ciphers $($you cannot use libraries$)$:

$$Simple Substitution

$$Double Transposition

$$RC$4$

Build a MySQL database that:

$-$Stores the input texts from that specific user $($if logged in$),$ the cipher used and the timestamp at the moment of the creation of the record.

$-$Stores the information related to the user accounts $($username$,$ password and email$)$ in the most secure way of your knowledge.

$$All these fields must be validated:

$$The username can contain English letters $($capitalized or not$),$ digits, and the characters $\text{'}\_\text{'}($underscore$)$ and $\text{'}-\text{'}($dash$).$ Nothing else.

$$The email must be well formatted.

$$The password can have limitations of your choice, if you think it's worth it$.$