Automatic Search for a Maximum Probability Differential Characteristic in a Substitution-Permutation Network

The algorithm presented in this paper computes a maximum probability differential characteristic in a Substitution-Permutation Network (or SPN). Such characteristics can be used to prove that a cipher is practically secure against differential cryptanalysis or on the contrary to build the most effective possible attack. Running in just a few second on 64 or 128-bit SPN, our algorithm is an important tool for both cryptanalists and designers of SPN

Partition-Based Trapdoor Ciphers

This paper deals with block ciphers embedding a trapdoor which consists to map a partition of the plaintext space to a partition of the ciphertext space. In a first part, this issue is reduced to the study of the S-boxes of the cipher satisfying a few criteria. Then, differential and linear properties of such S-boxes are assessed and an algorithm to build optimal S-boxes is provided. Finally, these primitives are used to design a small trapdoor cipher resistant to linear and differential cryptanalysis. This trapdoor allows to recover the $\kappa$-bit master key with only one plaintext/ciphertext pair and an effort of $2^{\frac{\kappa}{2}}$ encryptions

Stroke, thromboembolism and bleeding in patients with atrial fibrillation according to the EHRA valvular heart disease classification

Aims: We compared thromboembolic (TE) and bleeding risks in patients with atrial fibrillation (AF) according to the new ‘Evaluated Heartvalves, Rheumatic or Artificial’ (EHRA) valve classification.Methods: Patients were divided into 3 categories: (i) EHRA type 1 corresponds to the previous ‘valvular’ AF patients, with either rheumatic mitral valve stenosis or mechanical prosthetic heart valves; (ii) EHRA type 2 includes AF patients with other valvular heart disease (VHD) and valve bioprosthesis or repair; and (iii) ‘non-VHD controls’ i.e. all AF patients with neither VHD nor post-surgical valve disease.Results: Among 8962 AF patients seen between 2000 and 2010, 357 (4%) were EHRA type 1, 1754 (20%) were EHRA type 2 and 6851 (76%) non-VHD controls. EHRA type 2 patients were older and had a higher CHA2DS2-VASc and HAS-BLED scores than either type 1 and non-VHD patients. After a mean follow-up of 1264 ± 1160 days, the occurrence of TE events was higher in EHRA type 2 than non-VHD patients (HR (95%CI): 1.30 1.09–1.54), p = 0.003; also, p = 0.31 for type 1 vs 2, p = 0.68 for type 1 vs non-VHD controls). The rate of major BARC bleeding events for AF patients was higher in either EHRA type 1 (HR (95%CI): 3.16(2.11–4.72), p < 0.0001) or type 2 (HR (95%CI): 2.19(1.69–2.84), p < 0.0001) compared to non-VHD controls.Conclusion: The EHRA valve classification of AF patients with VHD appears useful in categorizing these patients, in terms of TE and bleeding risks. This classification can be used in clinical practice for appropriate choices of oral anticoagulation therapy and follow-up

Search for the standard model Higgs boson in the H to ZZ to 2l 2nu channel in pp collisions at sqrt(s) = 7 TeV

A search for the standard model Higgs boson in the H to ZZ to 2l 2nu decay channel, where l = e or mu, in pp collisions at a center-of-mass energy of 7 TeV is presented. The data were collected at the LHC, with the CMS detector, and correspond to an integrated luminosity of 4.6 inverse femtobarns. No significant excess is observed above the background expectation, and upper limits are set on the Higgs boson production cross section. The presence of the standard model Higgs boson with a mass in the 270-440 GeV range is excluded at 95% confidence level.Comment: Submitted to JHE

Combined search for the quarks of a sequential fourth generation

Results are presented from a search for a fourth generation of quarks produced singly or in pairs in a data set corresponding to an integrated luminosity of 5 inverse femtobarns recorded by the CMS experiment at the LHC in 2011. A novel strategy has been developed for a combined search for quarks of the up and down type in decay channels with at least one isolated muon or electron. Limits on the mass of the fourth-generation quarks and the relevant Cabibbo-Kobayashi-Maskawa matrix elements are derived in the context of a simple extension of the standard model with a sequential fourth generation of fermions. The existence of mass-degenerate fourth-generation quarks with masses below 685 GeV is excluded at 95% confidence level for minimal off-diagonal mixing between the third- and the fourth-generation quarks. With a mass difference of 25 GeV between the quark masses, the obtained limit on the masses of the fourth-generation quarks shifts by about +/- 20 GeV. These results significantly reduce the allowed parameter space for a fourth generation of fermions.Comment: Replaced with published version. Added journal reference and DO

Search for a W' boson decaying to a bottom quark and a top quark in pp collisions at sqrt(s) = 7 TeV

Results are presented from a search for a W' boson using a dataset corresponding to 5.0 inverse femtobarns of integrated luminosity collected during 2011 by the CMS experiment at the LHC in pp collisions at sqrt(s)=7 TeV. The W' boson is modeled as a heavy W boson, but different scenarios for the couplings to fermions are considered, involving both left-handed and right-handed chiral projections of the fermions, as well as an arbitrary mixture of the two. The search is performed in the decay channel W' to t b, leading to a final state signature with a single lepton (e, mu), missing transverse energy, and jets, at least one of which is tagged as a b-jet. A W' boson that couples to fermions with the same coupling constant as the W, but to the right-handed rather than left-handed chiral projections, is excluded for masses below 1.85 TeV at the 95% confidence level. For the first time using LHC data, constraints on the W' gauge coupling for a set of left- and right-handed coupling combinations have been placed. These results represent a significant improvement over previously published limits.Comment: Submitted to Physics Letters B. Replaced with version publishe

Measurement of the Z/gamma* + b-jet cross section in pp collisions at 7 TeV

The production of b jets in association with a Z/gamma* boson is studied using proton-proton collisions delivered by the LHC at a centre-of-mass energy of 7 TeV and recorded by the CMS detector. The inclusive cross section for Z/gamma* + b-jet production is measured in a sample corresponding to an integrated luminosity of 2.2 inverse femtobarns. The Z/gamma* + b-jet cross section with Z/gamma* to ll (where ll = ee or mu mu) for events with the invariant mass 60 < M(ll) < 120 GeV, at least one b jet at the hadron level with pT > 25 GeV and abs(eta) < 2.1, and a separation between the leptons and the jets of Delta R > 0.5 is found to be 5.84 +/- 0.08 (stat.) +/- 0.72 (syst.) +(0.25)/-(0.55) (theory) pb. The kinematic properties of the events are also studied and found to be in agreement with the predictions made by the MadGraph event generator with the parton shower and the hadronisation performed by PYTHIA.Comment: Submitted to the Journal of High Energy Physic

Measurement of the t t-bar production cross section in the dilepton channel in pp collisions at sqrt(s) = 7 TeV

The t t-bar production cross section (sigma[t t-bar]) is measured in proton-proton collisions at sqrt(s) = 7 TeV in data collected by the CMS experiment, corresponding to an integrated luminosity of 2.3 inverse femtobarns. The measurement is performed in events with two leptons (electrons or muons) in the final state, at least two jets identified as jets originating from b quarks, and the presence of an imbalance in transverse momentum. The measured value of sigma[t t-bar] for a top-quark mass of 172.5 GeV is 161.9 +/- 2.5 (stat.) +5.1/-5.0 (syst.) +/- 3.6(lumi.) pb, consistent with the prediction of the standard model.Comment: Replaced with published version. Included journal reference and DO

Search for New Physics with Jets and Missing Transverse Momentum in pp collisions at sqrt(s) = 7 TeV

A search for new physics is presented based on an event signature of at least three jets accompanied by large missing transverse momentum, using a data sample corresponding to an integrated luminosity of 36 inverse picobarns collected in proton--proton collisions at sqrt(s)=7 TeV with the CMS detector at the LHC. No excess of events is observed above the expected standard model backgrounds, which are all estimated from the data. Exclusion limits are presented for the constrained minimal supersymmetric extension of the standard model. Cross section limits are also presented using simplified models with new particles decaying to an undetected particle and one or two jets