Personal
page: Dr. Tomáš Rosa
I was born in 1974 in Prague, Czech Republic. Twenty five years later, I received M.Sc. degree in theoretical
computer science at the Faculty of Electrical Engineering (FEE) at
the Czech Technical University in Prague (CTU in Prague). The theme of my doctoral
dissertation thesis reads “Modern Cryptology: Standards Are Not Enough”
(online version of the Ph.D. thesis). It was
honored by the Best Doctoral Work Award of the Rector of Czech Technical University in Prague for the
year of 2004. As an external lecturer and researcher, I cooperate with the Department of Algebra
of the Faculty of
Mathematics and Physics of the Charles University and the Department of Computer Science of FEE CTU in Prague. My hobbies are (besides
the cryptology and mathematics) traveling, skiing, pipe collecting, and the
Tea. Here is a personal page of my colleague and friend Dr. Vlastimil Klíma who I often
cooperate on research projects with. You can also find some of our joint
publications there.
Membership: Cryptoworld (CZ)
Quick Links: Cryptology For Practice (CZ), PicNic
– HF RFID Emulator/Spyware
Work experience:
2004 – yet Senior
Cryptologist with Raiffeisenbank (merged
with eBanka in summer 2008)
Having successfully
established information security department for eBanka (c.f. bellow), I enjoy
working in the department as a senior cryptologist, or broadly speaking as an
information security mathematician. That means solving information security
problems using formal models and methods. As a leader in online banking
systems, eBanka requires its systems to be under close and continuous security
supervision during their design and maintenance. That presents me various very
interesting problems from the area of modern cryptology. Besides that I also
closely participate on design and implementation of the whole information
security strategy of eBanka.
2003 – 2004
Information Security Director with eBanka
The mission of this job was
to provide technology vision and leadership to start developing and
implementing information security program in the modern dynamic bank. I was responsible for establishing a
secure environment for its information assets. That included, but was not
limited to: security surveys and risk analyses, development of security
policies, standards, procedures and guidelines, design and analysis of security
countermeasures, intrusion detection, incident handling, disaster recovery
planning, etc. Besides this position I continued working on cryptology
research, mainly in the area of applied cryptography and cryptanalysis. In
fact, this job gave me very good inspiration for that, since I could easily
recognize how modern cryptology fits into the whole puzzle of information
security. Seeing the lack of essential cryptologic knowledge together with
facing its practical consequences motivated our joint (with Dr. Vlastimil Klíma) effort on
writing an easy to read, easy to understand, and easy to get serial on Cryptology for Practice.
2001 – 2003 Chief Cryptologist with ICZ Co.
As the chief cryptologist,
I managed and also participated on projects in the area of applied
cryptographic research. This mainly included joint work with the Czech
National Security Authority (CNSA)
on cryptographic devices designated to protect sensitive information at various
security levels, including the TOP SECRET level (according to the law 148/1998 Coll.,
Czech Republic). In 2001 and 2003, on behalf of my results achieved, I
received a special award of the board of directors and CEO of ICZ Co.
1997 – 2001
Development Specialist, Development Manager with Decros Ltd.
Here, as an information
security specialist, I started working on an implementation and a design of
cryptographic countermeasures into various protection devices. Since 1999, I
managed the security department which was focused on the joint work with CNSA on the development of the
special purpose cryptographic devices.
1993 – 1999
Independent Security Consultant & Publicist
Besides various
consultations, studies and expert’s findings, I worked on a security devices
evaluation in testing laboratories of the computer magazine CHIP (in Czech Republic).
Research area:
Cryptology, Side Channel
Cryptanalysis, Cryptographic Algorithms and Protocols, Quantum Cryptography,
Quantum Cryptanalysis, Risk Analysis, Mathematical Foundations of Information Security,
Security Management, and Information Management
Lecture notes and publications:
- Cryptology for Practice. A serial aimed to serve
as a basic handbook of modern applied cryptology. It should mainly be
useful for security architects and cryptology students (undergraduate
level). Also, several notes on RFID security are presented there. (CZ)
- Selected
lecture notes on RFID security: Smartcard
Forum 2009, Teleinformatika
2009. (CZ)
- Problems
arising around non-repudiation of digital
signatures as an inspiration for quantum cryptologists, University of
Palacky, October 7, Olomouc, 2004. (CZ)
- Lectures on
Applied Cryptography at the Faculty of Mathematics and
Physics, Charles University, 2003, 2004, 2005. (CZ)
- Security Policy – a Document of Various
Looks and Purposes, lecture for security managers and directors
at IT Security 2004, staged by the Institute
for International Research, Wien. (CZ)
- Lecture on special cryptanalysis held for colleagues at the Department of Computer Science, June
2003 (zipped ppt, syllabus). (CZ)
Research projects and publications (selected ones):
- Hlaváč, M. and Rosa, T.: A Note on the Realay-Attacks on
e-passports – The Case of Czech e-passports, IACE ePrint archive 2007/244, Jun 2007.
- Hlaváč, M. and Rosa, T.: Extended
Hidden Number Problem and Its Cryptanalytic Applications, in Proc.
of SAC 2006, LNCS 4356, pp. 114-133, Springer-Verlag, 2007.
- Rosa, T.: Cryptographic
Insecurity of the Test&Repeat Paradigm, NATO Advanced Research
Workshop - Security and Embedded Systems, University of Patras, Greece, 2005. (slides in ppt)
- Rosa, T.: Lattice-based
Fault Attacks on DSA - Another Possible Strategy, in Proc. of
Security and Protection of Information 2005, pp. 91-96, Brno, 2005.
- Rosa, T.: Non-repudiation of
digital signatures, in Proc. of 2nd Scientific and
Pedagogical Conference at ZMVS:
Juridical Regulation of Networked Society, Trebic, September 2004. Slides
used for the presentation are here.
The paper identifies an insufficiency of a strictly logical approach to
the subject of non-repudiation. It warns about problems arising on the edge
between mathematical and juridical reasoning and sketches possible
solutions. (CZ)
- Dissertation thesis, mainly on Side
Channel Cryptanalysis.
- Klíma, V., Pokorný, O., and Rosa, T.: Attacking RSA-based Sessions in SSL/TLS, in Proc. of CHES 2003, Cologne, Germany, September 2003, pp. 426-440, Springer-Verlag, 2003. For an extended version, see IACR ePrint archive 2003/052, March 2003. For the
press release of ICZ, see here. Slides used
for the presentation are here.
- Klíma, V., Rosa, T.: Side
Channel Attacks on CBC Encrypted Messages in the PKCS#7 Format, in Proc. of
Security and Protection of Information 2002, NATO PfP/PWP - 2nd
International Scientific Conference Security and Protection of
Information, Brno, Czech Republic, 28th – 30th of
April 2003.
- Klíma, V. and Rosa, T.: Further Results and Considerations on
Side Channel Attacks on RSA, in Proc. of CHES 2002, San Francisco Bay, USA,
August 2002, pp.
245-260 , Springer-Verlag, 2002. Slides used for the presentation are here.
- Klíma, V. and Rosa, T.: Strengthened Encryption in the
CBC Mode,
IACR ePrint archive 2002/061, May 2002.
- Rosa, T.: On
the Key-collisions in the Signature Schemes, in Proc. of workshop
VKB 2002, pp. 14-26, 2002, Brno, CZ. These slides
belong to the Czech version of the paper.
The paper won the best presentation award on the workshop VKB 2002. The
paper differs from the one presented at CRYPTO 2002 Rump Session in that
it also discuses k-collisions in RSA schemes. On the other hand the
paper listed bellow is more general and it also elaborates possible
countermeasures more deeply and precisely.
- Rosa, T.: Key-collisions
in (EC)DSA: Attacking Non-repudiation, CRYPTO 2002 Rump Session,
IACR ePrint
archive 2002/129, Santa Barbara, USA, August 2002. Slides used for the Rump Session presentation are
available here.
- Rosa, T.: Future
Cryptography: Standards are not Enough, in Proc. of Security and
Protection of Information 2001, NATO PfP/PWP – 1st International Scientific Conference
Security and Protection of Information, Brno, Czech Republic,
9th – 11th of May 2001.
- Klíma, V.
and Rosa, T.: Attack on
Private Signature Keys of the OpenPGP format, PGP (TM) Programs and Other
Applications Compatible with OpenPGP, IACR ePrint archive 2002/076, version 1, March
2001, minor update on June 2002. A short presentation viewing the whole attack
from a side channels point of view is here: ppt
slides, pdf
version of slides.
- Kupča, V.
and Rosa, T.: Theory and
Perspectives of Quantum Computers, in Proc. of Workshop 2001 -
Part A, pp. 192-193, CTU Prague, 2001. This short article summarizes the
results of diploma thesis presented by Vojtěch Kupča at the Department of
Computer Science at FEE, CTU in Prague, and led by Tomáš Rosa.
Other Activities:
- Time to
time, you can see my contributions at the Czech cryptologic news
server. The aim of the server is to bring reader’s attention at fresh,
but also certainly matured topics related to cryptology and-or information
security. (CZ)
- Here you
can find an interview with me
done for a weekend supplement of the newspaper Hospodářské noviny in May 2003. Partly, it
is based on our attack on
SSL/TLS (c.f. above). (CZ)
Last update: November 28th,
2009.
tomas_dot_rosa
(at) rb_dot_cz