Amazon Bedrock Agents enable generative AI applications to perform multistep tasks across various company systems and data sources. They orchestrate and analyze the tasks and break them down into the correct logical sequences using the reasoning abilities of the foundation model (FM). Agents automatically call the necessary APIs to interact with the company systems and processes to fulfill the request. Throughout this process, agents determine whether they can proceed or if additional information is needed.
Customers can build innovative generative AI applications using Amazon Bedrock Agents’ capabilities to intelligently orchestrate their application workflows. When building such workflows, it can be challenging for customers to apply fine-grained access controls to make sure that the application’s workflow operates only on the authorized data based on the application user’s entitlements. Controlling access to resources based on user context, roles, actions and resource conditions can be challenging to maintain in an application workflow because that would require hardcoding several rules in your application or building your own authorization system to externalize those rules.
Instead of building your own authorization system for fine-grained access controls in your application workflows, you can integrate Amazon Verified Permissions into the agent’s workflow to apply contextually aware fine-grained access controls. Verified Permissions is a scalable permissions management and authorization service for custom applications built by you. Verified Permissions helps developers build secure applications faster by externalizing the authorization component and centralizing policy management and administration.
In this post, we demonstrate how to design fine-grained access controls using Verified Permissions for a generative AI application that uses Amazon Bedrock Agents to answer questions about insurance claims that exist in a claims review system using textual prompts as inputs and outputs. In our insurance claims system use case, there are two types of users: claims administrators and claims adjusters. Both are capable of listing open claims, but only one is capable of reading claim detail and making changes. We also show how to restrict permissions using custom attributes such as a user’s region for filtering insurance claims. In this post, the term region doesn’t refer to an AWS Region, but rather to a business-defined region.
Solution overview
In this solution design, we assume that the customer has claims records in an Amazon DynamoDB table and would like to build a chat-based application to answer frequently asked questions about their claims. This chat assistant will be used internally by claims administrators and claims adjusters to answer their clients’ questions.
The following is a list of actions that the claims team needs to perform to answer their clients’ questions:
Show me a list of my open claims
Show me claim detail for an input claim number
Update the status to closed for the input claim number
The customer has the following access control requirements for their claims system:
A claims administrator can list claims across various geographic areas, but they can’t read individual claim records
A claims adjuster can list claims for their region and can read and update the records of claims assigned to them. However, a claims adjuster can’t access claims from other regions.
is placed into a group in Amazon Cognito, where their application-level permissions are set and maintained
The customer would like to use Verified Permissions to externalize entity and record level authorization decisions without hard coding the application logic
To improve the performance of the chat assistant, the customer uses FMs available on Amazon Bedrock. To retrieve the necessary information from the claims table and dynamically orchestrate the requests, the customer uses Amazon Bedrock Agents together with Verified Permissions to provide fine-grained authorization for the agents’ invocation.
The application architecture for building the example chat-based Generative AI Claims application with fine-grained access controls is shown in the following diagram.
The application architecture flow is as follows:
User accesses the Generative AI Claims web application (App).
The App authenticates the user with the Amazon Cognito service and issues an ID token and an access tokenID token has the user’s identity and custom attributes.
Using the App, the user sends a request asking to “list the open claims.†The request is sent along with the user’s ID token and access token. The App calls the Claims API Gateway API to run the claims proxy passing user requests and tokens.
Claims API Gateway runs the Custom Authorizer to validate the access token.
When access token validation is successful, the Claims API Gateway sends the user request to the Claims Proxy.
The Claims Proxy invokes the Amazon Bedrock agent passing the user request and ID token. The Amazon Bedrock agent is configured to use Anthropic’s Claude model and to invoke actions using the Claims Agent Helper AWS Lambda
Amazon Bedrock Agent uses chain-of-thought-prompting and builds the list of API actions to run with the help of Claims Agent Helper.
The Claims Agent Helper retrieves claim records from Claims DB and constructs a claims list object. For this example, we are providing hard-coded examples in the Lambda function and no DynamoDB was added to the example solution provided. However, we provide the component on the architecture for representing real-life use cases where the data is stored outside the Lambda
The Claims Agent Helper retrieves the user’s metadata (that is, their name) from ID token, builds the Verified Permissions data entities, and makes the Verified Permissions authorization request. This request contains the principal (user and role), action (that is, ListClaim) and resource (Claim). Verified Permissions evaluates the request against the Verified Permissions policies and returns an Allow or Deny decision. Subsequently, the Claims Agent Helper filters the claims based on that decision. Verified Permissions has “default deny†functionality, meaning that in the absence of an explicit allow, the service defaults to an implicit deny. If there is an explicit Deny in the policies involved in the request, Verified Permissions denies the request.
The Claims Amazon Bedrock Agent receives the authorized list of claims, augments the prompt and sends it to the Claude model for completion. The agent returns the completion back to the user.
Fine-grained access control flows
Based on the customer’s access control requirements, there are three fine-grained access control flows as depicted in the following system sequence diagrams.
Use case: Claims administrator can list claims across regions
The following diagram shows how the claims administrator can list claims across regions.
The following diagram depicts how the claims administrator’s fine-grained access to the claim record is run. In this diagram, notice a deny decision from Verified Permissions. This is because the principal’s role isn’t ClaimsAdjuster.
Use case: Claims adjuster can see claims they own
The following diagram depicts how the claims adjuster’s fine-grained access to retrieve claim details is run. In this diagram, notice the allow decision from Verified Permissions. This is because the principal’s role is ClaimsAdjuster and the resource owner (that is, claim owner) matches the user principal (that is, user=alice).
The following diagram depicts how the claims adjuster’s fine-grained access to list open claims is run. In this diagram, notice the allow decision from Verified Permissions. This is because the principal’s group is ClaimsAdjuster and the region on the resource matches the principal’s region. As a result of this region filter on the authorization policy, only open claims for the user’s region are returned. Verified Permissions acts on principal, action, and individual resource (that is, a claim record) for the authorization decision. Therefore, the Lambda function needs to iterate through the list of open claims and make an isAuthorized request for each claim record. If this results in a performance issue, you can use the BatchIsAuthorized API and send multiple authzRequest in one API call.
Entities design considerations
When designing fine-grained data access controls, it is best practice to start with the entity-relationship diagram (ERD) for the application. For our claims application, the user will operate on claim records to retrieve a list of claims records, get the details for an individual claim record, or update the status of a claim record. The following diagram is the ERD for this application modeled in Verified Permissions. With Verified Permissions, you can apply both role-based access control (RBAC) and attribute-based access control (ABAC).
Here is a brief description of each entity and attributes that will be used for RBAC and ABAC against claim records.
Application – The application is a chat-based generative AI application using Amazon Bedrock Agents to understand the questions and retrieve the relevant claims data to assist claims administrators and claims adjusters.
Claim – The claim represents an insurance claim record that is stored in the DynamoDB table. The claims system stores claim records and the chatbot application allows users to retrieve and update these records.
User – The user.
Role – The role represents a user’s access within the application. Here is a list of available roles:
Claims administrators – Can list claims across various geographic regions, but they can’t read individual claim records
Claims adjusters – Can list claims for their region and read and update their claim records
The roles are managed through Amazon Cognito and Verified Permissions. Cognito maintains a record of which role a user is assigned to and includes this information in the token. Verified Permissions maintains a record of what that role is permitted to do. Fine-grained access controls exist to make sure that users have appropriate permissions for their roles, restricting access to sensitive claim data based on geographic regions and user groups.
Fine-grained authorization: Policy design
The Actions diagram view lists the types of Principals you have configured in your policy store, the Actions they are eligible to perform, and the Resources they are eligible to perform actions on. The lines between entities indicate your ability to create a policy that allows a principal to take an action on a resource. The following image shows the actions diagram from Verified Permissions for our insurance claims use case. The User principal will have access to the Get, List, and Update actions. The resources are the Application and the Claim entity within the application. This diagram generates the underlying schema that governs the policy definition.
Use case: Claims administrator can list all claim records across regions
A policy is a statement that either permits or forbids a principal to take one or more actions on a resource. Each policy is evaluated independently of other policies. The Verified Permissions policy for this use case is shown in the following code example. In this policy, the principal (that is, user Bob), is assigned the role of claims administrator.
Use case: Claims administrator can’t access claim detail record
The Verified Permissions policy for this use case is shown in the following code example. The use of explicit “forbid†policies is a valid practice.
Use case: Claims adjuster can list claims they own in their region
The Verified Permissions policy for this use case is shown in the following code example. In this policy, the principal (that is, user Alice) is assigned the role of claims adjuster and their region is passed as a custom attribute in the ID token.
Use case: Claims adjuster can retrieve or update a claim they own
Authentication design considerations
The configuration of Amazon Cognito for this use case followed the security practices included as part of the standard configuration workflow: a strong password policy, multi-factor authentication (MFA), and a client secret. When using Amazon Cognito with Verified Permissions, your application can pass user pool access or identity tokens to Verified Permissions to make the allow or deny decision. Verified Permissions evaluates the user’s request based on the policies it has stored in the policy store.
For custom attributes, we are using region to restrict which claims a claims adjuster can see, excluding claims made in regions outside the adjuster’s own region. We are also using role as a custom attribute to provide that information in the ID token that is passed to the Amazon Bedrock agent. When the user is registered in the Cognito user pool, these custom attributes will be recorded as part of the sign-up process.
Amazon Cognito integrates with Verified Permissions through the Identity sources section in the console. The following screenshot shows that we’ve connected our Cognito user pool to the Amazon Verified Permissions policy store.
Fine-grained authorization: Passing ID token to the Amazon Bedrock agent
When the user is authenticated against the Cognito user pool, it returns an ID token and access token to the client application. The ID token will be passed through an API gateway and a proxy Lambda through SessionAttributes on the invoke_agent call.
The header is then retrieved from the Lambda event in the Action Group Lambda function and Verified Permissions is used to verify the user’s access against the desired action.
Fine-grained authorization: Integration with Amazon Bedrock Agents
The ID token issued by Cognito contains the user’s identity and custom attributes. This ID token is passed to the Amazon Bedrock agent, and the Agent Helper Lambda retrieves that token from the agent’s session attribute. Then, the Agent Helper Lambda retrieves open claim records from DynamoDB and constructs the Verified Permissions schema entities and makes the isAuthorized API call.
Because Verified Permissions resources operate at the individual record level (that is, a single claim record), you need to iterate over the claims list object and make the isAuthorized API call for the authorization decision and then create the filtered claims list. The filtered claims list is then passed back to the caller. As a result, the claims adjuster will only see claims for their region, while a claims administrator can see claims across all regions.
The Amazon Bedrock agent then uses this filtered claim list to complete the user’s request to list claims. The chat application can only access the claims records that the user is authorized to view, providing the fine-grained access control integrated with the Amazon Bedrock agent workflow.
Getting started
Check out our code to get started developing your secure generative AI application using Amazon Verified Permissions. We provide you with an end-to-end implementation of the architecture described in this post and a demo UI you can use to test the permissions of different users. Update this example to implement generative AI applications that connect with your use case setup.
Conclusion
In this post, we discussed the challenges in applying fine-grained access controls for agent workflows in a generative AI application. We shared an application architecture for building an example chat-based generative AI application that uses Amazon Bedrock Agents to orchestrate workflows and applies fine-grained access controls using Amazon Verified Permissions. We discussed how to design fine-grained access permissions through the design of persona-based access control workflows. If you are looking for a scalable and secure way to apply fine-grained permissions to your generative AI agent-based workflows, give this solution a try and leave your feedback.
About the authors
Ram Vittal is a Principal ML Solutions Architect at AWS. He has over 3 decades of experience architecting and building distributed, hybrid, and cloud applications. He is passionate about building secure, scalable, reliable AI/ML and big data solutions to help enterprise customers with their cloud adoption and optimization journey to improve their business outcomes. In his spare time, he rides his motorcycle and walks with his three-year old sheep-a-doodle!
Samantha Wylatowska is a Solutions Architect at AWS. With a background in DevSecOps, her passion lies in guiding organizations towards secure operational efficiency, leveraging the power of automation for a seamless cloud experience. In her free time, she’s usually learning something new through music, literature, or film.
Anil Nadiminti is a Senior Solutions Architect at AWS specializing in empowering organizations to harness cloud computing and AI for digital transformation and innovation. His expertise in architecting scalable solutions and implementing data-driven strategies enables companies to innovate and thrive in today’s rapidly evolving technological landscape.
Michael Daniels is an AI/ML Specialist at AWS. His expertise lies in building and leading AI/ML and generative AI solutions for complex and challenging business problems, which is enhanced by his PhD from the Univ. of Texas and his MSc in computer science specialization in machine learning from the Georgia Institute of Technology. He excels in applying cutting-edge cloud technologies to innovate, inspire, and transform industry-leading organizations while also effectively communicating with stakeholders at any level or scale. In his spare time, you can catch Michael skiing or snowboarding.
Maira Ladeira Tanke is a Senior Generative AI Data Scientist at AWS. With a background in machine learning, she has over 10 years of experience architecting and building AI applications with customers across industries. As a technical lead, she helps customers accelerate their achievement of business value through generative AI solutions on Amazon Bedrock. In her free time, Maira enjoys traveling, playing with her cat, and spending time with her family someplace warm.
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