LLM API Security Proxy for Prompt Injection and Data Leak Screening

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Solution Overview

Problem

Large Language Models (LLMs) face significant security challenges due to vulnerabilities in their APIs, including sensitive data leaks, prompt injection attacks, data poisoning, insecure output handling, denial-of-service attacks, permission issues, and excessive agency, which threaten the integrity and reliability of the data they process and generate.

Innovation Solution

Implement a system that utilizes a security LLM to generate feature vectors representing API calls, detect security threats, and determine security policies to be applied by a security proxy, incorporating data sanitization, access control, and ongoing vulnerability testing to safeguard LLMs against these attacks.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If LLMs are accessed through publicly available APIs, then the models can provide immense value across various sectors, but the models become vulnerable to security threats such as data leaks, prompt injection attacks, and denial-of-service attacks

Engineering Contradiction:
Improveaccessibility of LLMsVSAvoidsecurity threats to LLMs
Core Design Contradiction:
Adaptability or versatilityVSObject-affected harmful factors

Solution Approach 1:

The patent introduces a security proxy as an intermediary component between external API calls and the LLM. This proxy acts as a mediator that screens and filters incoming API requests before they reach the LLM, blocking malicious inputs while allowing legitimate requests to pass through. The security proxy thus enables the LLM to remain accessible through public APIs while protecting it from security threats.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The system performs preliminary security screening of API calls before they are processed by the LLM. By generating feature vectors from API call data and using a security LLM to detect potential threats in advance, the system proactively identifies and blocks malicious requests before they can compromise the LLM, thus preventing security incidents rather than reacting to them.

Inventive Principle:
Principle #10Preliminary action

2Reliability

If security systems are employed to counteract threats, then the security posture improves, but the complexity of the system increases

Engineering Contradiction:
Improvesecurity postureVSAvoidsystem complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The security system is segmented into distinct functional components: a security proxy for initial filtering, feature vector generation for data representation, a security LLM for threat detection, and a security policy determination module for decision-making. This segmentation allows each component to perform its specific function independently, making the overall security system more manageable and maintainable while providing comprehensive protection.

Inventive Principle:
Principle #1Segmentation

3Adaptability or versatility

If the number of APIs increases to support more services, then the functionality expands, but the difficulty of detecting and measuring security threats increases

Engineering Contradiction:
Improvefunctionality of API ecosystemVSAvoidthreat detection difficulty
Core Design Contradiction:
Adaptability or versatilityVSDifficulty of detecting and measuring

Solution Approach 1:

The system transforms the complex, unstructured data from diverse API calls into standardized feature vectors that capture essential characteristics of each request. By changing the representation parameters of API call data into a uniform numerical format, the security LLM can efficiently detect patterns and threats across different API types without being overwhelmed by the diversity and volume of incoming requests.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentUS20250373656A1Foundational machine learning model application programming interface (API) security
Publication Date: 2025.12.04 CEQUENCE SECURITY INC
  • US20250373656A1 patent drawing
  • US20250373656A1 patent drawing
  • US20250373656A1 patent drawing

AI summary

Various embodiments include a system. The system comprises processing circuitry. The processing circuitry obtains an Application Programming Interface (API) call that is associated with a Large Language Model (LLM). The processing circuitry generates a feature vector that numerically represents data included in the API call associated with the LLM. The processing circuitry provides the feature vector to a security LLM trained to detect security threats to the LLM. The processing circuitry obtains an output from the security LLM that indicates a security threat to the LLM. The processing circuitry determines a security policy based on the security threat. The processing circuitry provides the security policy to a security proxy that screens the API call.