Can you unhash a password php?

The best way to encrypt and decrypt passwords is to use a standard library in PHP because the method of properly encrypting and decrypting passwords from scratch is complex and involves multiple possibilities of security vulnerabilities. Using the standard library ensures that the hashing implementation is verified and trusted.

Note: This uses the PHP Password API available in version 5.5.0 and above.

Encryption of the password: To generate a hash from the string, we use the password_hash() function.

Syntax:

string password_hash(string $password, 
          mixed $algo, [array $options])

The password_hash() function creates a new password hash of the string using one of the available hashing algorithm. It returns the hash that is currently 60 character long, however, as new and stronger algorithms will be added to PHP, the length of the hash may increase. It is therefore recommended to allocate 255 characters for the column that may be used to store the hash in database.

The following algorithms are currently supported when using this function:

  • PASSWORD_DEFAULT
  • PASSWORD_BCRYPT
  • PASSWORD_ARGON2I
  • PASSWORD_ARGON2ID

Additional options can be passed to this function can be used to set the cost of encryption, the salt to be used during hashing, etc in the $options array.

The below example shows the method of using the password_hash() method:

Example:

php

  $plaintext_password = "Password@123";

  $hash = password_hash($plaintext_password

          PASSWORD_DEFAULT);

  echo "Generated hash: ".$hash;

?>

Output:

Generated hash: $2y$10$7rLSvRVyTQORapkDOqmkhetjF6H9lJHngr4hJMSM2lHObJbW5EQh6

Decryption of the password: To decrypt a password hash and retrieve the original string, we use the password_verify() function.

Syntax:

bool password_verify(string $password, string $hash)

The password_verify() function verifies that the given hash matches the given password, generated by the password_hash() function. It returns true if the password and hash match, or false otherwise.

php

  $plaintext_password = "Password@123";

  $hash

"$2y$10$8sA2N5Sx/1zMQv2yrTDAaOFlbGWECrrgB68axL.hBb78NhQdyAqWm";

  $verify = password_verify($plaintext_password, $hash);

  if ($verify) {

      echo 'Password Verified!';

  } else {

      echo 'Incorrect Password!';

  }

?>

Output:

Password Verified!

PHP is a server-side scripting language designed specifically for web development. You can learn PHP from the ground up by following this PHP Tutorial and PHP Examples.


One of the most important parts of a website is the authentication system and it is commonplace for developers to commit mistakes leaving out vulnerabilities for others to exploit. Since PHP is a server-side scripting language, it is responsible for all the back-end functionalities required by the website. In this article, we will learn how to decrypt md5 password in PHP in the following sequence:

  • Why do we need MD5 in PHP? 

  • What is MD5 hashing?

  • How to use MD5 in PHP?

  • Syntax

  • How to Decrypt MD5 Passwords in PHP?

  • Examples

Let’s begin.

Why do we need MD5 in PHP? 

One basic example could be storing and using user passwords in its true form, in this situation an unauthorized person might get access to the database and the whole system is compromised. To prevent this situation password hashing is used. Password hashing can be defined as a method that takes the user password or string and encrypts it into a fixed-length password, PHP has a few functions to achieve the same like md5(), sha1(), hash(). 

What is MD5 hashing?

MD5 hashing algorithm generates a 32 characters string (hexadecimal) for any word or phrase we give in the input. We can even encrypt an entire file into an MD5 hash. The algorithm can also be used for digital signature applications, where a large file is compressed in a secure manner and then encrypted with the help of a private key.

How to use MD5 in PHP?

To calculate the MD5 hash of a string PHP has a pre-defined function md5(). The md5() function calculates the MD5 hash of a string input and returns the hash hexadecimal number. The md5() function uses the MD5 Message-Digest Algorithm.

Syntax:

   md5(string,raw)

Parameter

Description

string

Mandatory. It is the input string that needs to be calculated

raw

Optional. Specifies binary or hex output format:

  • If it is set to TRUE – Raw 16 character binary format

  • If it is set to FALSE – Default. 32 character hex number

Return Type: 

md5() returns hash as a 32-character hexadecimal number.

How to Decrypt MD5 Passwords in PHP?

The MD5 cryptographic algorithm is not reversible i.e. We cannot decrypt a hash value created by the MD5 to get the input back to its original value. So there is no way to decrypt an MD5 password. But, we can use something like brute force hacking, which is extremely resource-intensive, not practical, and unethical. Thus, if someone is entering the correct password, we need to find the hash value of whatever the user entered, and see if it matches what we have in our database thus it is time and resource-intensive job to perform.

It is possible to guess what the original password is by looking in dictionaries of MD5 hashes of many known words, these dictionaries can be useful to tell a user that the password that he has chosen may be easily discovered thus we can ask the user to build a more strong password.

Examples to Decrypt MD5 Password

Example 1:

";  
echo "Hex formed by md5 function is ".md5($string);  
?>  

Output:

Can you unhash a password php?

In the above example, we print the hash value of “ PHP with Edureka” generated by the md5() function.

Example 2:

 

Output:

Can you unhash a password php?

In the above example, we check if the hash value of variable $string is equal to 9a1359e7be2d2670780b85471675dc72 the program prints out “PHP with Edureka is Fun” else it prints “look for the error”

Example 3

";   
echo "Setting raw input to TRUE getting 16 character binary: ".md5($string, TRUE)."
"; echo "default raw input set to FALSE giving 32 charater hex number: ".md5($string)."
"; ?>

Output:

Can you unhash a password php?

In the above example, we look at the application of the raw parameter in the md5() function. If we set it to TRUE it gives a 16 character binary output else it simply gives 32 characters hex number.

Example 4:

 Correct password ";
	}
	else{
		echo "
Incorrect password "; } } ?>

Output:

The above code gives an output of an HTML form with a text block and a submit button if we enter the correct password it prints “Correct password” else it prints “Incorrect password”.

Can you unhash a password php?

When we type in the wrong password for example here it checks for the hash of “pass” input with the hash of “pass123” the correct password if it does not match it gives out as follows

Can you unhash a password php?

It prints out  “Incorrect password”

Can you unhash a password php?

If we type in the right password (i.e “pass123”) the hash of the input matches with the hash of the correct password and it gives the following output

Can you unhash a password php?

It prints out “Correct password”

Can you unhash a password php?

Now with this, we have come to the end of the PHP Tutorial. I hope you guys enjoyed this article and understood the concepts of decryption. So, with the end of this PHP Tutorial, you are no longer a newbie to the scripting language.

If you found this PHP Tutorial blog relevant, check out the PHP Certification Training by Edureka, a trusted online learning company with a network of more than 250,000 satisfied learners spread across the globe.

Got a question for us? Please mention it in the comments section of ”How to decrypt md5 password in PHP?” and I will get back to you.

Is it possible to Unhash a password?

Encryption is a two-way function; what is encrypted can be decrypted with the proper key. Hashing, however, is a one-way function that scrambles plain text to produce a unique message digest. With a properly designed algorithm, there is no way to reverse the hashing process to reveal the original password.

Can bcrypt passwords be decrypted?

bcrypt is not an encryption function, it's a password hashing function, relying on Blowfish's key scheduling, not its encryption. Hashing are mathematical one-way functions, meaning there is no* way to reverse the output string to get the input string.

Can you decrypt MD5?

No, it is not possible to reverse a hash function such as MD5: given the output hash value it is impossible to find the input message unless enough information about the input message is known.

Can bcrypt hash be reversed?

You can't decrypt the hash, because - as you said - hash functions can't be reversed. You should still change your passwords.