In July 2011, Marc became the first Heisenberg Professor at Darmstadt University of Technology (TUDa), Germany, and established the group “Cryptography and Complexity Theory” (Cryptoplexity) at the Department of Computer Science. The group was initially funded by the German Research Foundation (DFG) as part of the Heisenberg Program until June 2016.
Marc is also a PI of the National Center for Applied Cybersecurity, ATHENE, co-funded by the Federal Ministry of Education and Research and the State of Hesse since January 2019. ATHENE continues the "Center for Research in Security and Privacy" (CRISP), which was also co-funded by the Federal Ministry of Education and Research and the State of Hesse from October 2015 to December 2018. CRISP unites the former “Center for Advanced Security Research Darmstadt” (CASED), funded by the State Hesse from September 2008 till June 2016, and the former "Competence Center for IT Security" (EC-Spride), funded by the Federal Ministry of Education and Research from October 2011 till September 2015. From October 2019 to June 2026, Marc also served as the speaker for the DFG-funded collaborative research center "Cryptography-based Security Solutions: Enabling trust in new and next generation computing environments" (CROSSING), which began in October 2014.
From February 2006 till January 2011, Marc was the head of the Emmy Noether research group “Minimizing Cryptographic Assumptions” (MiniCrypt). This group was also located at the Darmstadt University of Technology and funded by the German Research Foundation as part of the Emmy Noether Program.
From September 2004 to August 2005, Marc was affiliated with the Information Security and Cryptography Group in the Computer Science Department at Eidgenössische Technische Hochschule Zürich (ETH Zurich). This visit was primarily funded by the Emmy Noether Fellowship of the German Research Foundation (DFG) and in part by ETH Zurich.
From September 2003 to August 2004, Marc visited the Cryptography Group in the Computer Science and Engineering Department (CSE) at the University of California, San Diego (UCSD). This visit was funded by the Emmy Noether Program.
From June 2002 to August 2003, Marc worked at the Fraunhofer Gesellschaft, Institute for Secure Information Technology (SIT), formerly known as the Institute for Secure Telecooperation, Department of Security and Smartcard Technology (SICA). There, he was mainly involved in industry-related security projects.
From June 1997 to April 2002 (suspended for community service in 1998), Marc worked as a research assistant and Ph.D. student in Prof. Schnorr's group at the University of Frankfurt. His research during that time mainly dealt with the design of efficient and provably secure cryptographic protocols. He completed his Ph.D. in December 2001 with a grade of “summa cum laude”. The title of his thesis was “Trapdoor Commitment Schemes and Their Applications”.
From 1992 till 1997 and 1998, respectively, Marc studied Mathematics and Computer Science at the Johann Wolfgang Goethe-University in Frankfurt, Germany, obtaining diplomas in both subjects. His theses, under the supervision of Prof. Schnorr, both dealt with cryptography: one with incremental cryptography, the other with fair exchange of digital signatures.