CircleCI has introduced OpenID Connect (OIDC) identity tokens to enhance security in CI/CD workflows by allowing CircleCI jobs to authenticate with cloud providers like AWS and Google Cloud Platform without using static credentials. OIDC, which builds upon OAuth 2.0, is an authentication protocol enabling cloud services to verify user identity and securely access resources. By configuring AWS or GCP to trust CircleCI's OIDC tokens, users can streamline workflows such as uploading to cloud storage or deploying to production, while reducing the need for frequent key rotations. The process involves setting up IAM roles and identity providers in AWS, or creating workload identity pools and service accounts in GCP, to permit temporary credentials for CircleCI jobs. CircleCI also provides orbs, reusable YAML configuration packages, to simplify these integrations. Advanced configurations can include attribute-based restrictions to enforce the principle of least privilege, ensuring that only authorized jobs or users can access specific resources, thereby enhancing security and operational efficiency in automated pipelines.