49 research outputs found
Side-channel attacks and countermeasures in the design of secure IC's devices for cryptographic applications
Abstract--- A lot of devices which are daily used have to guarantee the retention of sensible data. Sensible data are ciphered by a secure key by which only the key holder can get the data. For this reason, to protect the cipher key against possible attacks becomes a main issue. The research activities in hardware cryptography are involved in finding new countermeasures against various attack scenarios and, in the same time, in studying new attack methodologies. During the PhD, three different logic families to counteract Power Analysis were presented and a novel class of attacks was studied. Moreover, two different activities related to Random Numbers Generators have been addressed
Sub-nanomolar detection of biogenic amines by SERS effect induced by hairy Janus silver nanoparticles
Surface enhanced Raman scattering (SERS) is largely used as a transduction method for analytes detection in liquid and vapor phase. In particular, SERS effect was promoted by a plethora of different metal and semiconducting nanoparticles (NPs) and silver and gold nanoparticles appear particularly suitable for this application. Nevertheless, silver nanoparticles intrinsic propensity to aggregate in large clusters reduces the possibility to use naked nanoparticles in SERS applications, for this reason they are usually functionalized with organic molecules. This approach inhibits the aggregation process but, on the other hand, reduces the surficial area of the NPs able to interact with the analyte molecules. In the present work, we propose a simple method to obtain surficial anisotropic Janus silver nanoparticles: octadecylamine was used to stabilize the nanoparticles and to promote the deposition of the silver nanoparticles on a solid substrate. The AgNPs/octadecylamine nanostructures showed the typical “hairy” Janus morphology and a strong SERS effect was observed when two biogenic amines, i. e. 2-phenylethylamine and tyramine, were fluxed on the solid film. SERS phenomenon was studied as a function both of the chemical structure of the fluxed amine and of the distance between the aromatic moiety and the nanoparticle allowing to propose the AgNPs/octadecylamine Janus nanoparticles as an active layer for the detection of phenylethylamine and tyramine in picomolar concentration
Biocompatible Collagen Paramagnetic Scaffold for Controlled Drug Release
A porous collagen-based hydrogel scaffold was prepared in the presence of iron oxide nanoparticles (NPs) and was characterized by means of infrared spectroscopy and scanning electron microscopy. The hybrid scaffold was then loaded with fluorescein sodium salt as a model compound. The release of the hydrosoluble species was triggered and accurately controlled by the application of an external magnetic field, as monitored by fluorescence spectroscopy. The biocompatibility of the proposed matrix was also tested by the MTT assay performed on 3T3 cells. Cell viability was only slightly reduced when the cells were incubated in the presence of the collagen-NP hydrogel, compared to controls. The economicity of the chemical protocol used to obtain the paramagnetic scaffolds as well as their biocompatibility and the safety of the external trigger needed to induce the drug release suggest the proposed collagen paramagnetic matrices for a number of applications including tissue engeneering and drug delivery
Supramolecular amplification of amyloid self-assembly by iodination
Amyloid supramolecular assemblies have found widespread exploitation as ordered
nanomaterials in a range of applications from materials science to biotechnology.
New strategies are, however, required for understanding and promoting mature fibril
formation from simple monomer motifs through easy and scalable processes. Noncovalent
interactions are key to forming and holding the amyloid structure together. On the other hand,
the halogen bond has never been used purposefully to achieve control over amyloid
self-assembly. Here we show that single atom replacement of hydrogen with iodine,
a halogen-bond donor, in the human calcitonin-derived amyloidogenic fragment DFNKF
results in a super-gelator peptide, which forms a strong and shape-persistent hydrogel at
30-fold lower concentration than the wild-type pentapeptide. This is remarkable for such
a modest perturbation in structure. Iodination of aromatic amino acids may thus develop as
a general strategy for the design of new hydrogels from unprotected peptides and without
using organic solvents
SIDE-CHANNEL ATTACKS AND COUNTERMEASURES IN THE DESIGN OF SECURE IC's DEVICES FOR CRYPTOGRAPHIC APPLICATIONS
Abstract--- A lot of devices which are daily used have to guarantee the retention of sensible data. Sensible data are ciphered by a secure key by which only the key holder can get the data. For this reason, to protect the cipher key against possible attacks becomes a main issue. The research activities in hardware cryptography are involved in finding new countermeasures against various attack scenarios and, in the same time, in studying new attack methodologies. During the PhD, three different logic families to counteract Power Analysis were presented and a novel class of attacks was studied. Moreover, two different activities related to Random Numbers Generators have been addressed