openssl_seal Seal (encrypt) data intopenssl_seal stringdata stringsealed_data arrayenv_keys arraypub_key_ids &warn.experimental.func; Returns the length of the sealed data on success, or &false; on error. If successful the sealed data is returned in sealed_data, and the envelope keys in env_keys. openssl_seal seals (encrypts) data by using RC4 with a randomly generated secret key. The key is encrypted with each of the public keys associated with the identifiers in pub_key_ids and each encrypted key is returned in env_keys. This means that one can send sealed data to multiple recipients (provided one has obtained their public keys). Each recipient must receive both the sealed data and the envelope key that was encrypted with the recipient's public key. See also openssl_open.