ECQV-escrow Key Agreement for Secure Lawful Interception
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional systems for lawful interception of communication sessions often rely on weak cryptography, allowing unauthorized access and lacking mechanisms for secure, undetectable interception of session keys, which is a requirement for telecommunications standards like 3GPP.
Innovation Solution
A key agreement protocol using an ECQV-escrow system that escrows private keys and seeds for pseudorandom generators, allowing authorized parties to generate session keys by combining information stored across multiple trusted entities, ensuring secure and undetectable interception without compromising user participation or performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If weak cryptography is used for lawful interception, then interception capability is improved, but security against unauthorized access deteriorates
Solution Approach 1:
The system segments the session key generation into multiple components distributed across different parties (U and V each contribute secret values). The interception authority can only obtain partial information (escrowed values) but not the complete session key, which requires combining multiple secret components. This segmentation prevents unauthorized access while enabling lawful interception when proper authorization is obtained.
Solution Approach 2:
The patent introduces an intermediary escrow mechanism where trusted authorities deposit cryptographic values without being able to reconstruct session keys independently. The intermediary structure allows authorized interception through controlled key recovery while maintaining security against unauthorized parties who lack the necessary authorization credentials.
2Adaptability or versatility
If session keys are escrowed for interception, then lawful interception is improved, but detection of interception deteriorates
Solution Approach 1:
The system extracts the interception capability from the communication flow itself by using pre-established escrowed values that can be combined with ephemeral key material to derive session keys. This extraction allows interception to occur without injecting or modifying communication packets, making the interception undetectable to the communicating parties.
Solution Approach 2:
The escrowed values are deposited in advance during key generation, before any communication occurs. This preliminary action enables the interception authority to reconstruct session keys later without needing to intercept or analyze the actual communication traffic, ensuring complete undetectability.
3Reliability
If multiple trusted entities hold escrowed information, then security against compromise is improved, but system complexity deteriorates
Solution Approach 1:
The system segments the trust architecture into multiple independent entities (certificate authorities and interception authorities), each holding partial escrowed information. No single entity can compromise the entire system, as all escrowed values are required to reconstruct session keys. This segmentation improves security against compromise while maintaining manageable complexity through clear separation of duties.
Data Source
Figure 1
Figure 2
Figure 3
AI summary
In some implementations, a method for providing a session key to a third party includes identifying a private key associated with a public key certificate in response to an event. A session key for a communication session is based, at least in part, on the private key, an associated seed for a random number generator, and public keys assigned to user equipment participating in the communication session. The private key associated with the public key certificate is automatically transmitted to an interception authority. The interception authorities are configured to grant a third party access to the private key and the associated seed to in response to a request from a third party authorized to access the communication session.