Essam Ghadafi

Contact Details:
Department of Computer Science and Creative Technologies
University of the West of England
Office 3Q64B, Frenchay Campus
Bristol
BS16 1QY
United Kingdom
Email:  firstName.lastName[AT]uwe[DOT]ac[DOT]uk



About Me

I am a senior lecturer in the Department of Computer Science and Creative Technologies. Prior to joining UWE (March 2017), I worked with Prof Jens Groth as a research associate in the Information Security Group at University College London from 2015 to 2017. Prior to that, I was at the Computer Science Department at the University of Bristol between 2011 and 2015 as a post-doctoral researcher in the Cryptography Group and then as a teaching associate.

I obtained my PhD in Computer Science from the University of Bristol working on Cryptography & Information Security in 2012. My supervisors were: Prof Nigel Smart and Dr Bogdan Warinschi​.
I got my Master's (with Distinction) from the University of Bristol in 2007 and my MSc project on multi-authority key-agreement protocols won the best advanced MSc project in security award..

Between obtaining my first degree and starting my Master's, I have worked for a number of years as a Programmer & System Analyst.

Research Interests

I am primarily interested in Cryptography & Information Security.


Current/Past Research

My research centeres around privacy-preserving cryptographic protocols. Topics I have worked on include:
  • Digital Cash.
  • Structure-Preserving Cryptography.
  • Direct Anonymous Attestation.
  • Attribute-Based Cryptography.
  • Proof systems and their applications.
  • Signature schemes and related primitives (e.g. blind signatures, Group Signatures, Ring Signatures, etc.).
  • Public-Key Encryption.


In the Press:


Publications:

  • E. Ghadafi. Further Lower Bounds for Structure-Preserving Signatures in Asymmetric Bilinear Groups. AFRICACRYPT 2019, pp. 409-428, July 2019.
    PDF [Full Paper] [Slides] Bibtex

  • E. Ghadafi. How Low Can You Go? Short Structure-Preserving Signatures for Diffie-Hellman Vectors. Coding and Cryptography: IMACC 2017, pp. xxx-xxx, December 2017.
    PDF [Full Paper] [Slides] Bibtex

  • A. EL Kaafarani and E. Ghadafi . Attribute-Based Signatures with User-Controlled Linkability without Random Oracles. Coding and Cryptography: IMACC 2017, pp. xxx-xxx, December 2017.
    PDF [Full Paper] [Slides] Bibtex

  • E. Ghadafi. Subset Signatures with Controlled Context-Hiding. Coding and Cryptography: IMACC 2017, pp. xxx-xxx, December 2017.
    PDF [Full Paper] [Slides] Bibtex

  • J. Bootle, A. Cerulli, E. Ghadafi , J. Groth, M. Hajiabadi, and S.K. Jakobsen. Linear-Time Zero-Knowledge Proofs for Arithmetic Circuit Satisfiability. Advances in Cryptology--ASIACRYPT 2017, pp. xxx-xxx, December 2017.
    PDF [Full Paper] [Slides] Bibtex

  • E. Ghadafi and J. Groth. Towards a Classification of Non-interactive Computational Assumptions in Cyclic Groups. Advances in Cryptology--ASIACRYPT 2017, pp. xxx-xxx, December 2017.
    PDF [Full Paper] [Slides] Bibtex

  • E. Ghadafi. More Efficient Structure-Preserving Signatures - Or: Bypassing the Type-III Lower Bounds. European Symposium on Research in Computer Security--ESORICS 2017, pp. 117-136, September 2017.
    PDF [Full Paper] [Slides] Bibtex

  • E. Ghadafi. Efficient Round-Optimal Blind Signatures in the Standard Model. Financial Cryptography and Data Security 2017, pp. xxx-xxx, April 2017.
    PDF [Full Paper] [Slides] Bibtex

  • J. Bootle, A. Cerulli, P. Chaidos, E. Ghadafi, and J. Groth. Foundations of Fully Dynamic Group Signatures. ACNS 2016, pp. 117-136, June 2016.
    PDF [Full Paper] [Slides] Bibtex

  • E. Ghadafi. Short Structure-Preserving Signatures. CT-RSA 2016, pp. 305-321. February 2016.
    PDF [Full Paper] [Slides] Bibtex

  • J. Bootle, A. Cerulli, P. Chaidos, E. Ghadafi, Jens Groth and Christophe Petit. Short Accountable Ring Signatures Based on DDH. ESORICS 2015, pp. 243-265. September 2015.
    PDF [Full Paper] [Slides] Bibtex

  • E. Ghadafi. Stronger Security Notions for Decentralized Traceable Attribute-Based Signatures and More Efficient Constructions. CT-RSA 2015, pp. 391-409. April 2015.
    PDF [Full Paper] [Slides] Bibtex

  • E. Ghadafi. Efficient Distributed Tag-Based Encryption and its Application to Group Signatures with Efficient Distributed Traceability. Latincrypt 2014, pp. 327-347. September 2014.
    PDF [Full Paper] [Slides] Bibtex

  • A. El Kaafarani, L. Chen, E. Ghadafi, and J. H. Davenport. Attribute-Based Signatures with User-Controlled Linkability. CANS 2014.
    PDF [Full Paper] [Slides] Bibtex

  • A. El Kaafarani, E. Ghadafi, and D. Khader. Decentralized Traceable Attribute-Based Signatures.CT-RSA 2014, pp. 327-348. February 2014.
    PDF [Full Paper] [Slides] Bibtex

  • E. Ghadafi. Sub-linear Blind Ring Signatures without Random Oracles. Coding and Cryptography: IMACC 2013, pp. 304-323. December 2013.
    PDF [Full Paper] [Slides] Bibtex

  • D. Bernhard, G. Fuchsbauer and E. Ghadafi. Efficient Signatures of Knowledge and DAA in the Standard Model. Applied Cryptography and Network Security -- ACNS 2013. pp. 518-533.
    PDF [Full Paper] [Slides] Bibtex

  • E. Ghadafi. Sub-linear Blind Ring Signatures without Random Oracles. Coding and Cryptography: IMACC 2013, pp. 304-323. December 2013.
    PDF [Full Paper] [Slides] Bibtex

  • E. Ghadafi. Formalizing Group Blind Signatures and Practical Constructions in the Standard Model. Australasian Conference on Information Security and Privacy -- ACISP 2013. pp. 330-346.
    PDF [Full Paper] [Slides] Bibtex

  • D. Bernhard, G. Fuchsbauer, E. Ghadafi, N.P. Smart and B. Warinschi. Anonymous attestation with user-controlled linkability. Int. Journal of Information Security, 1615-5262, February 2013.
    PDF [Full Paper] [Slides] Bibtex

  • E. Ghadafi and N.P. Smart. Efficient Two-Move Blind Signatures in the Common Reference String Model. Information Security Conference -- ISC 2012.
    PDF [Full Paper] [Slides] Bibtex

  • E. Ghadafi, N.P. Smart and B. Warinschi. Groth-Sahai Proofs Revisited. Public Key Cryptography -- PKC 2010, pp. 177-192
    PDF [Full Paper] [Slides] Bibtex

  • E. Ghadafi, N.P. Smart and B. Warinschi. Practical zero-knowledge proofs for circuit evaluation. Coding and Cryptography: IMACC 2009, pp. 469-494. December 2009
    PDF [Full Paper] [Slides] Bibtex

  • Teaching:

    I have been involved in teaching the following courses:
    • Databases
    • Data Structures and Algorithms
    • Principle of Computing
    • Software Product Engineering
    • Cryptography
    • Object Oriented Programming with Java


    Research Visits

    • From 10th of February to 18th of March 2016, University of Oxford -- Oxford, UK.
    • From 1st of March 2013 to 31st of March 2013, Brown University -- Rhode Island, USA.

    Seminars & Talks

    • More Efficient Structure-Preserving Signatures: Or Bypassing the Lower Bounds. University of Oxford, Oxford – UK, March 2016. [PDF]
    • Decentralized Traceable Attribute-Based Signatures. University College London , London – UK, April 2015. [PDF]
    • Direct Anonymous Attestation. Brown University , Providence, RI – USA, March 2013. [PDF]
    • Direct Anonymous Attestation. Bath University , Bath – UK, February 2013. [PDF]


    Other Activities:

    • Program Committees:

    • External Reviewing:

      • IMACC 2011, Pairing 2010, PKC 2010, EUROCRYPT 2012, PKC 2012, ACM CCS 2012, ASIACRYPT 2013, EUROCRYPT 2014, CRYPTO 2014, PKC 2015, CT-RSA 2015, IMACC 2015, ASIACRYPT 2015, PKC 2016, ACNS 2016, CRYPTO 2016.


    Hobbies

    Cycling, Football and Swimming .

    My Calender