Arthur vs Robust Intelligence

Arthur is an AI performance and safety platform founded in 2018 and headquartered in New York City. The platform provides monitoring, explainability, and bias detection for production ML, plus Arthur Shield for LLM firewall and red-teaming. Arthur raised a $42M Series B in September 2022 led by Acrew Capital and Greycroft, bringing total funding to approximately $56M.

Robust Intelligence was a San Francisco-based AI security company co-founded in 2019 by Harvard computer science professor Yaron Singer and Kojin Oshiba. The company pioneered the concept of an 'AI Firewall' — a purpose-built platform that validates, stress-tests, and protects AI models from development through production. Key capabilities included algorithmic red teaming, automated model assessment, and proactive AI risk mitigation aligned to OWASP and MITRE ATLAS standards. Robust Intelligence was acquired by Cisco in October 2024 for a reported $400M and has been foundational to the development of Cisco AI Defense and Cisco Foundation AI. Its technology is now integrated into the Cisco Security Cloud, providing threat protection against prompt injection, data poisoning, jailbreaking, and unintentional model outcomes. The company raised $44M prior to acquisition across three rounds.