An Identity Broker is an intermediary security service that facilitates federated authentication and authorization between external identity providers and internal service providers, validating identity assertions and translating them into short-lived access tokens or credentials for workload authentication across organizational and security domain boundaries.
How It Works
In workload identity and access management architectures, identity brokers establish trust relationships with multiple heterogeneous identity providers using different authentication protocols (SAML 2.0, OpenID Connect, OAuth 2.0). When a workload requests access to a protected resource, the broker validates the workload’s identity assertion against configured trust policies, performs token exchange according to RFC 8693 standards, and facilitates credential issuance scoped to specific resources and operations.
According to NIST SP 800-63C, the broker processes federation metadata, which is a cryptographically signed document containing public keys, service endpoints, and security policies for all entities within the federation. The broker then issues temporary credentials with typical lifetimes of one to twelve hours, eliminating the need for workloads to manage long-lived secrets while enabling seamless authentication across cloud platforms, SaaS applications, and on-premises infrastructure.
Why This Matters for Modern Enterprises
Organizations deploying AI agents, microservices, and hybrid workloads face exponential growth in non-human identities. Identity brokers address the fundamental security challenge of enabling workloads in one environment (AWS, on-premises data centers, CI/CD pipelines) to authenticate and access resources in another (Azure, Google Cloud, SaaS platforms) without duplicating service accounts or distributing static credentials across security boundaries. For enterprises running multi-cloud architectures, brokers enable workload identity federation where applications authenticate using their native identity provider and receive short-lived tokens for cross-platform access.
According to RFC 8693 (OAuth 2.0 Token Exchange), this token exchange mechanism formalizes two key broker capabilities: delegation (where the broker acts on behalf of a subject to request access to resources) and impersonation (where the broker assumes the identity of another party for token issuance). This architectural pattern becomes critical when securing AI workloads that access sensitive APIs (OpenAI, Claude, Gemini) or data warehouses (Snowflake, BigQuery), where traditional API key management creates credential sprawl and compliance headaches. According to major cloud providers including AWS, Azure, and Google Cloud, identity brokering eliminates the security burden of rotating long-term credentials, reduces the risk of leaked secrets, and enables dynamic, policy-driven access control that adapts to workload context, security posture, and runtime conditions.
Common Challenges with Identity Brokers
Trust Relationship Complexity: Establishing and maintaining cryptographically verifiable trust between multiple identity providers and service providers requires careful management of federation metadata according to standards frameworks like NIST SP 800-63C and IETF RFC 8693. Organizations must configure certificate chains and trust anchors, validate federation metadata in JSON Web Key Sets or XML metadata documents, and implement attribute mapping rules to translate external identity claims to internal identity representations. Critical security considerations include validating token signatures using federation metadata, preventing subject collisions when multiple external identities map to the same internal principal, and implementing strict verification of federation trust boundaries.
Token Validation Overhead: According to RFC 8693 (OAuth 2.0 Token Exchange) and NIST SP 800-63C federation standards, brokers must validate every incoming identity assertion by checking cryptographic signatures according to JSON Web Key Sets (JWKS) or XML-based metadata, verifying issuer and audience claims, confirming token expiration timestamps, and performing nonce validation to prevent replay attacks—as specified in OpenID Connect Core 1.0. In high-throughput environments, this validation overhead can introduce latency if not properly architected with caching strategies and distributed validation patterns as described in NIST’s architectural guidance on federation infrastructure.
Protocol Translation Gaps: Different systems use incompatible authentication protocols, requiring brokers to facilitate token exchange between SAML assertions, OpenID Connect ID tokens, OAuth 2.0 access tokens, and platform-specific formats. According to RFC 8693 (OAuth 2.0 Token Exchange), brokers validate external identity tokens against configured trust policies and exchange them for short-lived, platform-specific credentials, with the broker issuing the credentials rather than adapting the original token’s properties. This exchange must preserve the security guarantees of both the source and target systems while ensuring the issued credentials are scoped appropriately for the target platform’s authorization requirements.
Configuration Drift and Policy Inconsistency: As organizations add new workloads, cloud platforms, and SaaS integrations, broker configurations can drift across environments. Maintaining consistent access policies, attribute mappings, and trust relationships becomes increasingly difficult without centralized policy management and governance frameworks.
How Aembit Helps
Aembit functions explicitly as an identity broker for workload IAM, positioning the brokering capability as its core architectural function.
The platform acts as an intermediary between client workloads (applications, scripts, AI agents) and server workloads (APIs, databases, services) across heterogeneous environments, eliminating static credential management through secretless authentication. Aembit’s broker architecture integrates with Trust Providers (AWS, Kubernetes, GitHub Actions) for cryptographic workload attestation and Credential Providers (Vault, cloud IAM systems) for short-lived credential issuance.
The centralized policy control plane enables organizations to define attribute-based access controls, conditional access policies based on security posture, and consistent governance across cloud, SaaS, and on-premises deployments. By automating the entire brokering workflow, Aembit removes the need for developers to write authentication logic or manage secret rotation, while providing comprehensive audit logs for every credential issuance event.
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FAQ
You Have Questions?
We Have Answers.
What is the difference between an identity broker and an identity provider?
An identity provider (IdP) is the authentication authority that manages identities and issues cryptographically signed assertions proving a workload authenticated successfully. An identity broker is the intermediary that validates these assertions from external IdPs, translates them across protocol boundaries, and facilitates credential exchange with target platforms. The IdP answers “who you are” while the broker enables “where you can go” by mediating trust between different security domains.
How does identity brokering differ from secrets management?
Secrets managers store and protect static sensitive values like API keys, passwords, and certificates in encrypted vaults. Identity brokers eliminate the need to store most secrets by facilitating dynamic credential issuance based on verified workload identity. Brokers validate identity assertions and enable temporary credential generation, while secrets managers focus on secure storage and access control for long-lived secrets that cannot be eliminated. The technologies are complementary: brokers reduce the number of secrets that need management, while secrets managers protect the remaining static credentials.
Can identity brokers work across multiple cloud providers simultaneously?
Modern identity brokers are explicitly designed for multi-cloud federation. Cloud platforms like AWS IAM Roles Anywhere, Azure Entra Workload Identity Federation, and Google Cloud Workload Identity Federation enable workloads running in one cloud to authenticate and access resources in another without duplicating service accounts or credentials. The broker establishes trust relationships with multiple cloud identity systems, validates tokens from any trusted source, and issues platform-specific credentials as needed. This cross-cloud capability is foundational to hybrid and multi-cloud architectures.
What token standards do identity brokers support?
Identity brokers implement RFC 8693 (OAuth 2.0 Token Exchange) as the universal protocol for token translation, supporting multiple input and output formats including OAuth 2.0 access tokens, OpenID Connect ID tokens, SAML 2.0 assertions, JSON Web Tokens (JWT), and platform-specific formats. According to RFC 8693 Section 3, the broker can accept a SAML assertion from an enterprise IdP and exchange it for an OAuth 2.0 access token, or translate a Kubernetes service account token into cloud provider credentials. This multi-protocol support enables brokers to mediate between legacy systems using SAML and modern cloud-native environments using OIDC without requiring application changes.