Description

openssl_private_encrypt(
 #[\SensitiveParameter] string $data,
 string &$encrypted_data,
 #[\SensitiveParameter] OpenSSLAsymmetricKey|OpenSSLCertificate|array|string $private_key,
 int $padding = OPENSSL_PKCS1_PADDING
): bool

openssl_private_encrypt() encrypts data with private private_key and stores the result into encrypted_data. Encrypted data can be decrypted via openssl_public_decrypt().

This function can be used e.g. to sign data (or its hash) to prove that it is not written by someone else.