Understanding LTI 1.3 Launch Handshake in Education…

What is an LTI 1.3 Launch Handshake?

The Learning Tools Interoperability (LTI) standard enables secure communication between learning management systems (LMS) and external tools, such as educational applications or assessment services. The launch handshake is a crucial part of this process, where an LMS Platform sends a request to the external Tool to initiate a session for a specific user.

In LTI 1.3, this interaction involves the exchange of signed JSON Web Tokens (JWT) that contain essential information about the user and the requested resource. These tokens are encrypted with a shared secret key, ensuring secure transmission over the network.

How Does the Launch Handshake Work?

The launch handshake begins when an LMS Platform sends a POST request to the external Tool’s endpoint, including a signed JWT. This token contains claims such as the user ID, tool consumer key, and resource link ID. The external Tool verifies the signature using its shared secret key to ensure the message's integrity.

Upon successful verification, the external Tool responds with another signed JWT containing session information. This process ensures that both parties are authenticated and authorized before establishing a secure connection.

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Why is Signature Verification Important?

Signature verification in LTI 1.3 is crucial for maintaining the integrity of the communication between the LMS Platform and the external Tool. By verifying the signature, both parties can confirm that the message has not been tampered with during transmission.

This process helps prevent unauthorized access and ensures that only valid requests are processed, enhancing overall security in educational technology systems.

Tamper Detection and Key Management

The launch handshake also includes mechanisms to detect tampering. If a signature is found to be invalid or if the JWKS (JSON Web Keys) key used for verification becomes stale, the external Tool can reject the request. This ensures that only valid keys are used for signing and verifying tokens.

To manage these issues, tools often include features like refreshing the JWKS key cache and handling stale keys, which is demonstrated in this simulation through a 'Refresh JWKS' button.

Frequently asked questions

What happens if the signature verification fails?

If the signature verification fails, the external Tool will reject the request to prevent unauthorized access and ensure data integrity.

How does the simulation help in understanding LTI 1.3 launches?

The simulation provides a hands-on experience by allowing you to trigger various scenarios such as tampering with signatures, refreshing JWKS keys, and handling stale key caches, thereby deepening your understanding of the launch handshake process.

Can an LTI 1.3 launch be used for any type of educational tool?

Yes, LTI 1.3 launches can be used with a wide range of educational tools, including learning applications, assessment services, and content providers, as long as they support the LTI standard.

Is LTI 1.3 launch handshake secure against all types of attacks?

While LTI 1.3 provides robust security features like signature verification and key management, it is still important to implement additional security measures and stay vigilant against evolving threats.

Try it live

Everything above runs in your browser — open LTI 1.3 Launch Handshake Simulator (2D) and change the parameters while it is running. Nothing is installed, nothing is uploaded, the whole model lives in one tab.

▶ Open LTI 1.3 Launch Handshake Simulator (2D) simulation

Understanding LTI 1.3 Launch Handshake in Education Technology