I'm using these attributes: var attributes: [String: Any] = [ kSecAttrKeyType as String: kSecAttrKeyTypeECSECPrimeRandom, kSecAttrKeyClass as String: kSecAttrKeyClassPrivate, kSecAttrKeySizeInBits as String: 256, kSecAttrAccessGroup as String: accessGroup, kSecAttrIsPermanent as String: true, kSecPrivateKeyAttrs as String: [ kSecAttrIsPermanent as String: true, kSecAttrAccessControl as String: access ] ]

privateKey is base64Encoded Data BNcHWtSeaQzOjwoHakZ66ojCFZV4uGU+VjRSAMOxd2NpwAEXHOarCV3yonOyJI5UIkJ1CCO+DbORtG83DDMkNuVmPGQu5nJiQCD9RfDA+UncG+woRrTrLDhAw6fHXD9DtA==