Securing Interactive Sessions Using Mobile Device through Visual Channel and Visual Inspection

Communication channel established from a display to a device's camera is known as visual channel, and it is helpful in securing key exchange protocol. In this paper, we study how visual channel can be exploited by a network terminal and mobile device to jointly verify information in an interactive session, and how such information can be jointly presented in a user-friendly manner, taking into account that the mobile device can only capture and display a small region, and the user may only want to authenticate selective regions-of-interests. Motivated by applications in Kiosk computing and multi-factor authentication, we consider three security models: (1) the mobile device is trusted, (2) at most one of the terminal or the mobile device is dishonest, and (3) both the terminal and device are dishonest but they do not collude or communicate. We give two protocols and investigate them under the abovementioned models. We point out a form of replay attack that renders some other straightforward implementations cumbersome to use. To enhance user-friendliness, we propose a solution using visual cues embedded into the 2D barcodes and incorporate the framework of "augmented reality" for easy verifications through visual inspection. We give a proof-of-concept implementation to show that our scheme is feasible in practice.Comment: 16 pages, 10 figure

Anisotropic Total Variation Regularized L^1-Approximation and Denoising/Deblurring of 2D Bar Codes

We consider variations of the Rudin-Osher-Fatemi functional which are particularly well-suited to denoising and deblurring of 2D bar codes. These functionals consist of an anisotropic total variation favoring rectangles and a fidelity term which measure the L^1 distance to the signal, both with and without the presence of a deconvolution operator. Based upon the existence of a certain associated vector field, we find necessary and sufficient conditions for a function to be a minimizer. We apply these results to 2D bar codes to find explicit regimes ---in terms of the fidelity parameter and smallest length scale of the bar codes--- for which a perfect bar code is recoverable via minimization of the functionals. Via a discretization reformulated as a linear program, we perform numerical experiments for all functionals demonstrating their denoising and deblurring capabilities.Comment: 34 pages, 6 figures (with a total of 30 subfigures); errors corrected in Version 3, see Errata 1.1, 4.4, and 6.6 (v3 numbering) for more informatio

Bar code standardization by creating new symbology

Ovaj članak predlaže novu tipizaciju bar koda koja pojednostavljuje korištenje bilo kojeg dvodimenzionalnog matričnog bar koda na tržištu iz perspektive korisnika, istovremeno poštujući pravila svakog od njih. Predlaganjem nove tipizacije postojeći funkcijski uzorci su prebačeni u digitalni prostor i dodatni su dijelovi ugrađeni. Dodavanjem dijela koji se zove obrub (the rim), bilo koji 2D matrični bar kod može imati iste funkcijske uzorke i biti prepoznatljiv korisniku, što omogućuje standardizaciju bar koda. Prateći korake u ovom članku, za svaki 2D matrični bar kod, obrub se može precizno izračunati. Nova tipizacija također može imati dva različita bar koda u isto vrijeme implementiranjem maski koje mogu transformirati bitove kako bi se formirao željeni grafiči uzorak. Ovim se istraživanjem pridonosi cijelokupnoj standardizaciji 2D matričnih bar kodova što će omogućiti korisnicima identificiranje bilo kojeg tipa 2D matričnog bar koda na isti način kao i druge 2D matrične bar kod tipizacije. Ovom metodom moguće je stvoriti jednostavnije bar kodove za korisnika.This paper proposes a new symbology which eases the use of any two-dimensional matrix bar code on the market from a user perspective, respecting the rules of each 2D matrix bar code. By proposing a new symbology, the exisiting function patterns are transfered into a digital space and additional parts are added. By adding a part called the rim, any 2D matrix bar code can have the same function patterns and can be recognizable to the user, which enables the bar code standardization. For each 2D matrix bar code the rim can be precisely calculated. It can also carry two different 2D bar codes by implementing masks which can rearrange bits to form the desired graphic pattern. This research will contribute overall 2D matrix bar code standardization which will enable users to identify 2D matrix bar codes in the same way as other 2D matrix bar code symbologies. With this method a more user friendly bar code can be achieved