Computer Laboratory

Alexandre Joannou

I am a Research Associate in the Computer Architecture Group at the University of Cambridge Computer Laboratory. I completed my PhD thesis , High-performance memory safety - Optimizing the CHERI capability machine, supervised by Professor Simon More. During my PhD, I worked on compressed capabilities and efficient tagged memory. I also worked on a formal model of the CHERI MIPS extensions, written in the L3 ISA modeling language. I am currently working on an ISA modeling framework in the Bluespec System Verilog language, and implementing a RISCV model.


  • Joannou, A. J. P. (2018). High-performance memory safety - Optimizing the CHERI capability machine (Doctoral thesis).
  • Robert N. M. Watson, Peter G. Neumann, Jonathan Woodruff, Michael Roe, Jonathan Anderson, John Baldwin, David Chisnall, Brooks Davis, Alexandre Joannou, Ben Laurie, Simon W. Moore, Steven J. Murdoch, Robert Norton, Stacey Son, Hongyan Xia. Capability Hardware Enhanced RISC Instructions: CHERI Instruction-Set Architecture (Version 6), Technical Report UCAM-CL-TR-907, Computer Laboratory, April 2017. Current CHERI ISA specification
  • Alexandre Joannou, Jonathan Woodruff, Robert Kovacsics, Simon W. Moore, Alex Bradbury, Hongyan Xia, Robert N. M. Watson, David Chisnall, Michael Roe, Brooks Davis, Edward Napierala, John Baldwin, Khilan Gudka, Peter G. Neumann, Alfredo Mazzinghi, Alex Richardson, Stacey Son, and A. Theodore Markettos. Efficient Tagged Memory. Proceedings of the 2017 IEEE 35th International Conference on Computer Design (ICCD). Boston, MA, USA, November 5-8, 2017.
  • David Chisnall, Brooks Davis, Khilan Gudka, David Brazdil, Alexandre Joannou, Jonathan Woodruff, A. Theodore Markettos, J. Edward Maste, Robert Norton, Stacey Son, Michael Roe, Simon W. Moore, Peter G. Neumann, Ben Laurie, and Robert N. M. Watson. CHERI-JNI: Sinking the Java security model into the C. Proceedings of the 22nd ACM International Conference on Architectural Support for Programming Languages and Operating Systems (ASPLOS 2017). Xi'an, China, April 8–12, 2017.
  • Robert N.M. Watson, Robert M. Norton, Jonathan Woodruff, Simon W. Moore, Peter G. Neumann, Jonathan Anderson, David Chisnall, Brooks Davis, Ben Laurie, Michael Roe, Nirav H. Dave, Khilan Gudka, Alexandre Joannou, A. Theodore Markettos, Ed Maste, Steven J. Murdoch, Colin Rothwell, Stacey D. Son, and Munraj Vadera. Fast Protection-Domain Crossing in the CHERI Capability-System Architecture. IEEE Micro vol. 36 no. 5, p. 38-49, Sept.-Oct., 2016