What authentication method allows connecting to a DB instance without using a password?

IAM DB Authentication is the authentication method that allows users to connect to a database instance without needing to use a password. This approach leverages AWS Identity and Access Management (IAM) to provide secure access to your database based on IAM policies. By enabling IAM DB Authentication, users are authenticated via AWS security credentials (such as those provided by IAM users or roles) and an authentication token, thereby eliminating the need to manage or embed database passwords within applications or scripts.

This method enhances security by providing fine-grained access control and allows administrators to manage permissions centrally through IAM policies, making it easier to audit and rotate credentials as needed. Additionally, by using credential tokens that expire, IAM DB Authentication minimizes the risk of long-lived database passwords being exposed.

With IAM DB Authentication, connections can be made seamlessly while complying with organizational security best practices regarding credential management.