Linköping University invites applications for a PhD position in communication systems, focusing on the cutting-edge area of AI security. The research topic is 'Memory Poisoning in LLM Agents: Foundations, Attacks, and Defenses.' Large language model (LLM) agents are revolutionizing artificial intelligence by integrating LLMs with external tools and memory components, enabling complex reasoning and decision-making. These agents are increasingly used in critical domains such as healthcare, finance, cybersecurity, and autonomous vehicles, where they interact with external knowledge sources and retain memory across sessions.

While LLM agents offer transformative benefits, they also face new and poorly understood security risks. Memory poisoning attacks, which exploit the agent’s ability to store and adapt knowledge, pose severe threats to reliability and security, potentially leading to biased decisions, manipulation, breaches, and system failures. The project aims to develop a theoretical foundation for understanding and mitigating these attacks, contributing to the forefront of AI security research.

The position is funded by the Swedish Research Council (VR) and is based in the Division for Communication Systems (KS), Department of Electrical Engineering (ISY), Linköping University. The division conducts research and education in communications engineering, statistical signal processing, network science, and decentralized machine learning. The research team includes Asst. Prof. Khac-Hoang Ngo (Linköping University), Prof. Alexandre Graell i Amat (Chalmers University of Technology), and Dr. Johan Östman (Recorded Future), with opportunities for research visits to Chalmers and Recorded Future. The team currently consists of 5 PhD students and 2 postdocs.

Linköping University is recognized as a leader in AI research, ranked 43rd globally and 12th in Europe, and has been awarded 'Student City of the Year' in Sweden three times. The PhD position is full-time for four years, with possible extensions based on teaching and departmental duties. Salary is determined by a locally negotiated progression, and employment benefits are provided.

Applicants must have a Master’s degree in Computer Science, Electrical Engineering, or Applied Mathematics (minimum 240 credits, with at least 60 in advanced courses), or equivalent knowledge. Strong mathematical maturity, programming skills, and excellent English communication are required. Candidates should be independent, goal-oriented, and effective collaborators. The degree requirement must be met by the time the employment contract is signed. The starting date is by agreement, but no later than January 1, 2027.

To apply, submit your application via the official job page by April 20, 2026. Late applications will not be considered. For questions, contact the department or request to connect with current PhD students. Linköping University values diversity and equal opportunities, and encourages applicants from varied backgrounds.