# Changeset 3626

Ignore:
Timestamp:
Mar 6, 2017, 7:22:26 PM (8 months ago)
Message:

Changes to main cerco.tex file:

Changed subtitle to something a little more snappy (still not really happy with it),
Rewrote abstract to be less defensive, too.

File:
1 edited

### Legend:

Unmodified
 r3619 the Seventh Framework Programme for Research of the European Commission, under FET-Open grant number: 243881}} \subtitle{Verified lifting of concrete complexity annotations through a realistic C compiler} \subtitle{} \journalname{Journal of Automated Reasoning} \titlerunning{Certified Complexity} \authorrunning{Boender, Campbell, Mulligan, and Sacerdoti~Coen} \institute{Jaap Boender \at Faculty of Science and Technology,\\ Middlesex University London,\\ United Kingdom.\\ Faculty of Science and Technology, Middlesex University London, United Kingdom.\\ \email{J.Boender@mdx.ac.uk} \and Brian Campbell \at Department of Informatics,\\ University of Edinburgh,\\ United Kingdom.\\ Department of Informatics, University of Edinburgh, United Kingdom.\\ \email{Brian.Campbell@ed.ac.uk} \and Dominic P. Mulligan \at Computer Laboratory,\\ University of Cambridge, \\ United Kingdom.\\ Computer Laboratory, University of Cambridge, United Kingdom.\\ \email{Dominic.Mulligan@cl.cam.ac.uk} \and Claudio Sacerdoti~Coen \at Dipartimento di Informatica---Scienza e Ingegneria (DISI),\\ University of Bologna,\\ Italy.\\ Dipartimento di Informatica---Scienza e Ingegneria (DISI), University of Bologna, Italy.\\ \email{Claudio.SacerdotiCoen@unibo.it}} \begin{abstract} We provide an overview of the FET-Open Project CerCo (Certified Complexity').  Our main achievement is the development of a technique for analysing non-functional properties of programs (time, space) at the source level with little or no loss of accuracy and a small trusted code base. Intensional properties of programs---time and space usage, for example---are an important component of the specification of a program, and therefore overall program correctness. Here, intensional properties can be analysed \emph{asymptotically}, or \emph{concretely}, with the latter analyses computing resource bounds in terms of clock cycles, bits transmitted, bytes allocated, or other basal units of resource consumption, for a program execution. For many application domains, for instance libraries exporting cryptographic primitives that must be hardened against timing side-channel attacks, concrete complexity analysis is arguably more important than asymptotic. The core component is a C compiler, verified in the Matita theorem prover, that produces an instrumented copy of the source code in addition to generating object code. Traditional static analysis tools for resource analysis suffer from a number of disadvantages. They are sophisticated, complex pieces of software, that must be incorporated into the trusted codebase of an application if their analysis is to be believed. They also reason on the machine code produced by a compiler, rather than at the level of the source-code that the application programmer is familiar with, and understands. More ideal would be a mechanism to lift' a cost model from the machine code generated by a compiler, back to the source code level, where analyses could be performed in terms of source code, abstractions, and control-flow constructs written and understood by the programmer. However: incorporating the precision of traditional static analyses into a high-level approach is a challenge, and how to do this reliably is not \emph{a priori} clear. In this paper, we describe the scientific achievements of the European Union's FET-Open Project CerCo (Certified Complexity'). CerCo's main achievement is the development of a technique for analysing intensional properties of programs at the source level, with little or no loss of accuracy and a small trusted code base. The core component of the project a C compiler, verified in the Matita theorem prover, that produces an instrumented copy of the source code, in addition to generating object code. This instrumentation exposes, and tracks precisely, the actual (non-asymptotic) computational cost of the input program at the source level. Untrusted invariant generators and trusted theorem provers may then be used to compute and certify the parametric execution time of the code. We describe the architecture of our C compiler, its proof of correctness, the associated toolchain developed around the compiler, as well as a case study in applying this toolchain to the verification of concrete timing bounds on cryptographic code. \keywords{Verified compilation \and Complexity analysis \and CerCo (Certified Complexity')} \end{abstract}