Bernardo Machado David

Email me: bernardo at cs.au.dk

About Me

I'm a Ph.D. student at the Computer Science Department of Aarhus University under the supervision of Ivan Damgård. I hold a MSc in Computer Science from Aarhus University and a B.E. in Network Engineering from the University of Brasilia. I have also spent six months at NTT Secure Plaftorm Laboratories working with Tatsuaki Okamoto and Masayuki Abe and six months at the Cryptography Group at Bar Ilan University working with Yehuda Lindell.

→Download my full CV

My Research

I'm interested in a broad range of topics in cryptography, information theory and network security. My current focus is on theoretical and practical aspects of secure multiparty computation and cryptographic protocols in general. Previously I have worked on coding based cryptography, information theoretical security, network intrusion detection, practical user authentication, online banking and cryptographic protocols.

→My Google Scholar Profile

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Publications

Here you can find a list of my publications in refereed journals and conferences. You can also access a partial list at my DBLP or Google Scholar Profile.

Conference Papers

Ignacio Cascudo, Ivan Damgård, Bernardo David, Nico Döttling, Jesper Buus Nielsen: Rate-1, Linear Time and Additively Homomorphic UC Commitments. In: Crypto 2016.

Bernardo David, Rafael Dowsley, Raj Katti, and Anderson C. A. Nascimento: Efficient Unconditionally Secure Comparison and Privacy Preserving Machine Learning Classification Protocols. In: Provsec 2015.

Bernardo David, Ryo Nishimaki, Samuel Ranellucci, Alain Tapp: Generalizing Efficient Multiparty Computation. In: ICITS 2015.

Ignacio Cascudo, Ivan Damgård, Bernardo David, Irene Giacomelli, Jesper Buus Nielsen, Roberto Trifiletti: Additively Homomorphic UC commitments with Optimal Amortized Overhead. In: PKC 2015.

Ivan Damgård, Bernardo David, Irene Giacomelli, Jesper Buus Nielsen: Compact VSS and Efficient Homomorphic UC Commitments. In: Asiacrypt 2014.

Bernardo David, Rafael Dowsley, Anderson C. A. Nascimento: Universally Composable Oblivious Transfer based on a variant of LPN. In: CANS 2014.

Masayuki Abe, Bernardo David, Markulf Kohlweiss, Ryo Nishimaki, Miyako Ohkubo: Tagged One-Time Signatures: Tight Security and Optimal Tag Size. In: PKC 2013.

Masayuki Abe; Melissa Chase; Bernardo David; Markulf Kohlweiss; Miyako Okhubo; Ryo Nishimaki. Constant-Size Structure Preserving Signatures: Generic Constructions and Simple Assumptions. In: Asiacrypt 2012.

Adriana Pinto; Bernardo David; Anderson C. A. Nascimento; Jeroen Van de Graaf. Universally Composable Committed Oblivious Transfer with a Trusted Initializer. In: SBSEG 2012. (Best Paper Award)

Bernardo David ; Anderson C. A. Nascimento; Joern Mueller-Quade. Universally Composable Oblivious Transfer From Lossy Encryption And The McEliece Assumptions. IN: ICITS 2012.

Bernardo David ; Anderson C. A. Nascimento . Efficient fully simulatable oblivious transfer from the McEliece assumptions. In: IEEE Information Theory Workshop (ITW), 2011.

QUELHO, R. T. M. ; Bernardo David ; Alves, V. M. . Universally Composable Private Proximity Testing. In: Provsec 2011.

Bernardo David ; QUELHO, R. T. M. ; Anderson C. A. Nascimento . Obtaining Efficient Fully Simulatable Oblivious Transfer from General Assumptions. In: SBSEG 2011.

Journal Papers

Masayuki Abe, Melissa Chase, Bernardo David, Markulf Kohlweiss, Ryo Nishimaki, Miyako Ohkubo. Constant-Size Structure-Preserving Signatures: Generic Constructions and Simple Assumptions. In: Journal of Cryptology (2015).

Bernardo David, Rafael Dowsley, Jeroen van de Graaf, Davidson Marques, Anderson C. A. Nascimento, Adriana C. B. Pinto. Unconditionally Secure, Universally Composable Privacy Preserving Linear Algebra. In: IEEE Transactions on Information Forensics and Security (2015).

Bernardo David; Anderson C. A. Nascimento. Fully Simulatable Oblivious Transfer Based on The McEliece Assumptions. In: IEICE Transactions 95-A(11): 2059-2066 (2012)

Network Security

Bernardo David ; Anderson C. A. Nascimento ; QUELHO, R. T. M. ; Rafael Timoteo de Sousa Junior . A framework for secure single sign-on. In: Workshop de Gestao de Identidades Digitais, SBSEG 2012.

Bernardo David; da Costa, J. P. C. L. ; Amaral, D. ; Rafael Timoteo de Sousa Junior ; FREITAS, E. P. ; SERRANO, A. M. R. . Improved Blind Automatic Malicious Activity Detection in Honeypot Data. In: ICoFCS 2012. (Best Paper Award)

Holtz, M. D. ; Bernardo David ; Sousa Jr., R. T. . An architecture for distributed Network Intrusion Detection based on the Map-Reduce Framework. In: IWT 2011.

Bernardo David ; da Costa, J. P. C. L. ; Anderson C. A. Nascimento ; Holtz, M. D. ; Amaral, D. ; Sousa Jr., R. T. . Blind Automatic Malicious Activity Detection in Honeypot Data. In: ICoFCS 2011.

Bernardo David ; Sousa Jr., R. T. . A Bayesian Trust Model for the MAC Layer in IEEE 802.15.4 Networks. In: I2TS 2011.

Bernardo David ; da Costa, J. P. C. L. ; Anderson C. A. Nascimento ; Holtz, Marcelo D. ; Amaral, D. ; Sousa Jr., R. T. . A Parallel Approach to PCA Based Malicious Activity Detection in Distributed Honeypot Data. The International Journal of Forensic Computer Science (Impresso), v. 6, p. 8-27, 2011.

Holtz, Marcelo D. ; Bernardo David ; Sousa Jr., R. T. . Building Scalable Distributed Intrusion Detection Systems Based on the MapReduce Framework. Telecomunicacoes (Santa Rita do Sapucai), v. 13, p. 22-31, 2011. (Invited by I2TS 2011 Program Committee)

Crypto & Research Links

Some interesting resources on cryptography, computer science, mathematics and research in general:

The MPC Lounge - All about the practical and theoretical aspects of secure multiparty computation.

IACR's Calendar of Conferences/Workshops/Events

Ivan Damgård's Homepage

Aarhus University Cryptography group

Oded Goldreich's Homepage

"in theory" - Luca Trevisan's blog

A Few Thoughts on Cryptographic Engineering " - Matthew Green's blog

Goedel's Lost Letter and P=NP - Richard Lipton's blog

Tim Gowers's blog

Quantum Frontiers - A blog by the Institute for Quantum Information and Matter @ Caltech

Post-quantum Cryptography - Nice introduction to Post-quantum Cryptography including a comprehensive bibliography

History of Aarhus Crypto Group - Directory of all current and past members of the Aarhus Crypto Group

Contact Me

Address: Department of Computer Science, Aabogade 34, 8200 Aarhus, Denmark. Office: Nygaard 284

Email: bernardo at cs.au.dk

Phone: (+45)29883541

Fun & Hobbies

Helicopter Division

I'm a proud member of the crypto group's Helicopter Division:

Fredagscaféen (Friday Bar)

You can always find me in the Computer Science (or another) local Friday Bar

https://www.fredagscafeen.dk/

Chemical Cryptography

I was involved in the creation of one of the most powerful frameworks of modern cryptography: Chemical Cryptography.

Get rid of undesirable computational assumptions and achieve perfect security with the power of C2H6O!

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DOWNLOAD: Chemical OT: On the (Im)possibility of Basing Oblivious Transfer on Chemical Assumptions (presented at the Rump Session of the first Aarhus MPC Workshop

Having Fun in Tokyo

As you may know I spent roughly 7 months in Tokyo while in an internship at NTT's crypto group, of course this gave me more than enough time to explore the city...

Here you can download my TCC 2013 Rump Session presentation about the best spots for having fun in Tokyo.