Dillon Dieffenbach
Critical infrastructure companies can no longer afford to accept less – we must treat cybersecurity as a fundamental component of system reliability.

Dillon G. Dieffenbach

EY Japan Cybersecurity Leader

People-first leader with a global mindset. Practical experience in protecting critical infrastructure. Strategic thinker. Problem solver. Team builder. Traveler, golfer, proud father and husband.

Dillon leads EY Japan cybersecurity teams, helping Japanese companies as well as organizations doing business in Japan, to improve their cyber risk profile. He provides specific cyber competency assessment and advisory services that are tailored to specific industry needs, as well as program and technology implementations support and cyber as a managed service offering.

His recent projects have helped client teams identify and mitigate cyber risks related to data and system availability, confidentiality, integrity, effectiveness, compliance and efficiency, especially within the Financial Services, Life Sciences and Critical Infrastructure industries.

Prior to joining EY, Dillon was responsible for leading IT compliance at a national US financial services company, where he reported directly to the CEO. There, he also assisted in defining and leading the execution of IT initiatives in support of the business strategy.

He has a bachelor’s degree in Accounting and Business Administration from Furman University.

How Dillon is building a better working world

“In my current role, I have the amazing opportunity to connect East and West. I assist in building teams across borders that work together to help the world’s leading companies better manage their cyber risks. In the transformative age, working with talented professionals to build and protect digital trust is my way of helping to build a better working world.”

Contact Dillon