How to make a personal algorithm for hash in PHP - php

Question

I want to make a personal algorithm for hashing texts in PHP. The letter 'a' crypt in 'xyz', 'b' in '256' and some more. How it's possible this?

Answer 1

It's possible by simple create a function that make characters substitution, like this:
function myEncrypt ($text)
{
$text = str_replace(array('a', 'b'), array('xby', '256'), $text);
// ... others
return $text;
}
version with two arrays "search" and "replaceWith" passed as arguments:
function myEncrypt ($text, $search=array(), $replaceWith=array())
{
return str_replace($search, $replaceWith, $text);
}
WARNING: That way isn't a correct solution to encrypt a text, there are a lot of better ways to do a secure encryption with PHP (see for example this post).

Answer 2

I'm bored at work so I thought i'd give this a crack.
This isn't secure at all. The crypt must be hard coded and the crypted character must have a size of 3.
<?php
//define our character->crypted text
$cryptArray = array( "a"=>"xyz","b"=>"256");
//This is our input
$string = "aab";
//Function to crypt the string
function cryptit($string,$cryptArray){
//create a temp string
$temp = "";
//pull the length of the input
$length = strlen($string);
//loop thru the characters of the input
for($i=0; $i<$length; $i++){
//match our key inside the crypt array and store the contents in the temp array, this builds the crypted output
$temp .= $cryptArray[$string[$i]];
}
//returns the string
return $temp;
}
//function to decrypt
function decryptit($string,$cryptArray){
$temp = "";
$length = strlen($string);
//Swap the keys with data
$cryptArray = array_flip($cryptArray);
//since our character->crypt is count of 3 we must $i+3 to get the next set to decrypt
for($i =0; $i<$length; $i = $i+3){
//read from the key
$temp .= $cryptArray[$string[$i].$string[$i+1].$string[$i+2]];
}
return $temp;
}
$crypted = cryptit($string,$cryptArray);
echo $crypted;
$decrypted = decryptit($crypted,$cryptArray);
echo $decrypted;
The input was : aab
The output is:
xyzxyz256
aab
Here's the 3v4l link:
https://3v4l.org/chR2A