Which Hashing Algorithm is Best for Secure Password Storage in PHP?

Secure Password Storage: SHA1 vs md5 vs SHA256 vs bcrypt

When designing a secure login system, the choice of hashing algorithm is crucial. The traditional options, SHA1, md5, and SHA256, have known vulnerabilities. While salt can mitigate these risks, it's important to consider more robust alternatives.

bcrypt: The Preferred Choice

The answer to "Which hashing algorithm to use for a PHP login?" is clear: bcrypt. Unlike SHA1, md5, and SHA256, bcrypt is designed for security, not speed. It uses a slower hashing process with complex rounds and salts to deter brute-force attacks.

PHP 5.5 Implementation

Modern versions of PHP (5.5 ) provide native bcrypt support through the password_hash() function:

<code class="php">// Creating a hash
$hash = password_hash($password, PASSWORD_DEFAULT, ['cost' => 12]);

// Verifying the password against the stored hash  
if (password_verify($password, $hash)) {
    // Success! Log the user in here.
}</code>

Older PHP Versions

For older versions of PHP, you can use the password_compat library to implement bcrypt:

<code class="php">// Creating a hash
$hash = password_compat_hash($password, PASSWORD_BCRYPT);

// Verifying the password against the stored hash  
if (password_compat_verify($password, $hash)) {
    // Success! Log the user in here.
}</code>

Cautions

bcrypt has two important caveats:

• It silently truncates passwords longer than 72 characters.
• It truncates after any NUL characters.

Instead of creating your own workaround, use a secure library such as ZendCrypt or PasswordLock.

Conclusion

For secure password storage in PHP, use bcrypt. It provides unparalleled protection against password cracking, ensuring the integrity of your login system.

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