This rule discourages the use of the SHA224 hashing algorithm and its variants such as SHA512/224 and SHA3-224. These hash functions produce shorter digests that offer less collision resistance compared to stronger alternatives like SHA256 or SHA512. Using SHA224 can weaken the security of your application, making it more vulnerable to collision attacks and reducing overall cryptographic strength.
To ensure robust security, it is important to use more secure hash algorithms such as SHA256 or SHA3-256, which provide longer digests and better resistance against cryptographic attacks. When calling PHP’s hash or hash_hmac functions, specify these stronger algorithms explicitly, for example: hash('sha256', $content, $key);.
