Static Analysis of Circuits for Security

The purpose of the present work is to define a methodology to analyze a system description given in VHDL code and test its security properties. In particular the analysis is aimed at ensuring that a malicious user cannot make a circuit output the secret data it contains

Accelerated partial breast irradiation using 3D conformal radiotherapy: Toxicity and cosmetic outcome

Purpose: The aim of this paper is to analyze the incidence of acute and late toxicity and cosmetic outcome in breast cancer patients submitted to breast conserving surgery and three-dimensional conformal radiotherapy (3D-CRT) to deliver accelerated partial breast irradiation (APBI). Methods and materials: 84 patients were treated with 3D-CRT for APBI. This technique was assessed in patients with low risk stage I breast cancer enrolled from September 2005 to July 2011. The prescribed dose was 34/38.5 Gy delivered in 10 fractions twice daily over 5 consecutive days. Four to five nocoplanar 6 MV beams were used. In all CT scans Gross Tumor Volume (GTV) was defined around the surgical clips. A 1.5 cm margin was added by defining a Clinical Target Volume (CTV). A margin of 1 cm was added to CTV to define the planning target volume (PTV). The doseevolume constraints were followed in accordance with the NSABP/RTOG protocol. Late toxicity was evaluated according to the RTOG grading schema. The cosmetic assessment was performed using the Harvard scale. Results: Median patient age was 66 years (range 51e87). Median follow-up was 36.5 months (range 13 e83). The overall incidence of acute skin toxicities was 46.4% for grade 1 and 1% for grade 2. The incidence of late toxicity was 16.7% for grade 1, 2.4% for grade 2 and 3.6% for grade 3. No grade 4 toxicity was observed. The most pronounced grade 2 late toxicity was telangiectasia, developed in three patients. Cosmetics results were excellent for 52%, good for 42%, fair for 5% and poor for 1% of the patients. There was no statistical correlation between toxicity rates and prescribed doses (p ¼ 0.33) or irradiated volume (p ¼ 0.45). Conclusions: APBI using 3D-CRT is technically feasible with very low acute and late toxicity. Long-term results are needed to assess its efficacy in reducing the incidence of breast relapse

The ZRTP Protocol - Analysis on the Diffie-Hellman mode

ZRTP is a key agreement protocol by Philip Zimmermann, Alan Johnston and Jon Callas, which relies on a Di e-Hellman exchange to generate SRTP session parameters, providing con dentiality and protecting against Man-in-the-Middle attacks even without a public key infrastructure or endpoint certi cates. This is an analysis of the protocol performed with ProVerif, which tests security properties of ZRTP; in order to perform the analysis, the protocol has been modeled in the applied pi -calculus

Towards a UTP-style framework to deal with probabilities

We present an encoding of the semantics of the probabilistic guarded command language (pGCL) in the Unifying Theories of Programming (UTP) framework. Our contribution is a UTP encoding that captures pGCL programs as predicate-transformers, on predicates over probability distributions on before- and after-states: these predicates capture the same information as the models traditionally used to give semantics to pGCL; in addition our formulation allows us to de?ne a generic choice construct, that covers conditional, probabilistic and non-deterministic choice. We introduce the concept of probabilistic re?nement in this framework. This technical report gives a rigourous presentation of our framework, along with a variety of proofs and examples (including the well-known Monty Hall problem), that help to explain it

A probabilistic theory of designs based on distributions

We present a theory of designs based on functions from the state space to real numbers, which we term distributions. This theory uses predicates, in the style of UTP, based on homogeneous relations between distributions, and is richer than the standard UTP theory of designs as it allows us to reason about probabilistic programs; the healthiness conditions H1{H4 of the standard theory are implicitly accounted for in the distributional theory we present. In addition we propose a Galois connection linkage between our distribution-based model of probabilistic designs, and the standard UTP model of (non-probabilistic) designs

Weakening the Dolev-Yao model through probability

The Dolev-Yao model has been widely used in protocol verificaion and has been implemented in many protocol verifiers. There are strong assumptions underlying this model, such as perfect cryptography: the aim of the present work is to propose an approach to weaken this hypothesis, by means of probabilistic considerations on the strength of crypto- graphic functions. Such an approach may effectively be implemented in actual protocol verifiers. The Yahalom proto- col is used as an easy example to show this approach

A formal security proof for the ZRTP protocol

When some agents want to communicate through a media stream (for example voice or video), the Real Time Protocol (RTP) is used. This protocol does not provide encryption, so it is necessary to use Secure RTP (SRTP) to secure the communication. In order for this to work, the agents need to agree on key material and ZRTP provides them with a procedure to perform this task: it is a key agreement protocol, which relies on a Diffie-Hellman exchange to generate SRTP session parameters, providing confidentiality and protecting against Man-in-the-Middle attacks even without a public key infrastructure or endpoint certificates. This is an analysis of the protocol performed with ProVerif, which tests security properties of ZRTP; in order to perform the analysis, the protocol has been modeled in the applied calculus