Javier Herranz, Ramiro Pinilla, Manuel Sánchez-Raya
In an electronic voting procedure, mixing networks are used to ensure anonymity of the casted votes. Each node of the network re-encrypts the input list of ciphertexts and randomly permutes it in a process named shuffle, and must prove (in zero-knowledge) that the process was applied honestly. To maintain security of such a process in a post-quantum scenario, new proofs are based on different mathematical assumptions, such as lattice-based problems. Nonetheless, the best lattice-based protocols to ensure verifiable shuffling have linear communication complexity on N, the number of shuffled ciphertexts.
The protocol for cryptocurrencies can be divided into three parts, namely consensus, wallet, and networking overlay. The aim of the consensus part is to bring trustless rational peer-to-peer nodes to an agreement to the current status of the blockchain. The status must be updated through valid transactions. A proof-of-work (PoW) based consensus mechanism has been proven to be secure and robust owing to its simple rule and has served as a firm foundation for cryptocurrencies such as Bitcoin and Ethereum. Specialized mining devices have emerged, as rational miners aim to maximize profit, and caused two problems: i) the re-centralization of a mining market and ii) the huge energy spending in mining. In this paper, we aim to propose a new PoW called Error-Correction Codes PoW (ECCPoW) where the error-correction codes and their decoder can be utilized for PoW. In ECCPoW, puzzles can be intentionally generated to vary from block to block, leading to a time-variant puzzle generation mechanism. This mechanism is useful in repressing the emergence of the specialized mining devices. It can serve as a solution to the two problems of recentralization and energy spending.
Numberlink is a logic puzzle for which the player has to connect all pairs of cells with the same numbers by non-crossing paths in a rectangular grid. In this paper, we propose a physical protocol of zero-knowledge proof for Numberlink using a deck of cards, which allows a player to physically show that he/she knows a solution without revealing it. In particular, we develop a physical protocol to count the number of elements in a list that are equal to a given secret value without revealing that value, the positions of elements in the list that are equal to it, or the value of any other element in the list. Our protocol can also be applied to verify the existence of vertex-disjoint paths connecting all given pairs of endpoints in any undirected graph.
Mikael Beyene, Kannengießer, Niclas, Pandl, Konstantin D, Thiebes, Scott · 5 authors
A concept for distributed gene-drug interaction data sharing based on Ethereum Smart Contracts. The data is stored in a map with, both, keys and values utilizing a mixed-radix integer encoding that relies on the finiteness of the domains of given genes, drugs, and interactions. Thus, we get random access and, further, data queries are reduced to cheap bit comparisons.
Open access
Innovative Microfluidic and Catalytic Techniques Innovation
Benjamin Hellouin de Ménibus, Ville Salo, Guillaume Theyssier
Abelian cellular automata (CAs) are CAs which are group endomorphisms of the full group shift when endowing the alphabet with an abelian group structure. A CA randomizes an initial probability measure if its iterated images have weak*-convergence towards the uniform Bernoulli measure (the Haar measure in this setting). We are interested in structural phenomena, i.e., randomization for a wide class of initial measures (under some mixing hypotheses). First, we prove that an abelian CA randomizes in Cesàro mean if and only if it has no soliton, i.e., a non-zero finite configuration whose time evolution remains bounded in space. This characterization generalizes previously known sufficient conditions for abelian CAs with scalar or commuting coefficients. Second, we exhibit examples of strong randomizers, i.e., abelian CAs randomizing in simple convergence; this is the first proof of this behaviour to our knowledge. We show, however, that no CA with commuting coefficients can be strongly randomizing. Finally, we show that some abelian CAs achieve partial randomization without being randomizing: the distribution of short finite words tends to the uniform distribution up to some threshold, but this convergence fails for larger words. Again this phenomenon cannot happen for abelian CAs with commuting coefficients.
Government officials and industry experts increasingly highlight today's data privacy and security vulnerabilities require new approaches to mitigate risk. Additional methods and techniques to address current vulnerabilities are needed especially between responsible parties within a large ecosystem like finance, healthcare, and education. New approaches leveraging cryptographic ledgers and blockchains are emerging as a potential solution. This paper proposes a layered architectural approach for cryptographic ledgers to aid in security and privacy controls of digital solutions.
A homomorphic public key crypto-scheme based on the Boolean Satisfiability Problem is proposed. The public key is a SAT formula satisfied by the private key. Probabilistic encryption generates functions implied to be false by the public key XOR the message bits. A zero-knowledge proof is used to provide signatures.
In this paper we present a new 5-pass identification scheme with asymptotic\ncheating probability 1/2 based on the syndrome decoding problem. Our protocol\nis related to the Stern identification scheme but has a reduced communication\ncost compared to previous code-based zero-knowledge schemes, moreover our\nscheme permits to obtain a very low size of public key and secret key. The\ncontribution of this paper is twofold, first we propose a variation on the\nStern authentication scheme which permits to decrease asymptotically the\ncheating probability to 1/2 rather than 2/3 (and very close to 1/2 in practice)\nbut with less communication. Our solution is based on deriving new challenges\nfrom the secret key through cyclic shifts of the initial public key syndrome; a\nnew proof of soundness for this case is given Secondly we propose a new way to\ndeal with hashed commitments in zero-knowledge schemes based on Stern's scheme,\nso that in terms of communication, on the average, only one hash value is sent\nrather than two or three. Overall our new scheme has the good features of\nhaving a zero-knowledge security proof based on well known hard problem of\ncoding theory, a small size of secret and public key (a few hundred bits), a\nsmall calculation complexity, for an overall communication cost of 19kb for\nauthentication (for a $2^{16}$ security) and a signature of size of 93kb\n(11.5kB) (for security $2^{80}$), an improvement of 40% compared to previous\nschemes based on coding theory.\n
In this paper we present a new 5-pass identification scheme with asymptotic cheating probability 1/2 based on the syndrome decoding problem. Our protocol is related to the Stern identification scheme but has a reduced communication cost compared to previous code-based zero-knowledge schemes, moreover our scheme permits to obtain a very low size of public key and secret key. The contribution of this paper is twofold, first we propose a variation on the Stern authentication scheme which permits to decrease asymptotically the cheating probability to 1/2 rather than 2/3 (and very close to 1/2 in practice) but with less communication. Our solution is based on deriving new challenges from the secret key through cyclic shifts of the initial public key syndrome; a new proof of soundness for this case is given Secondly we propose a new way to deal with hashed commitments in zero-knowledge schemes based on Stern's scheme, so that in terms of communication, on the average, only one hash value is sent rather than two or three. Overall our new scheme has the good features of having a zero-knowledge security proof based on well known hard problem of coding theory, a small size of secret and public key (a few hundred bits), a small calculation complexity, for an overall communication cost of 19kb for authentication (for a $2^{16}$ security) and a signature of size of 93kb (11.5kB) (for security $2^{80}$), an improvement of 40% compared to previous schemes based on coding theory.
We proposed a new zero-knowledge proof of identity protocol based on Mandelbrot and Julia Fractal sets. The Fractal based zero-knowledge protocol was possible because of the intrinsic connection between the Mandelbrot and Julia Fractal sets. In the proposed protocol, the private key was used as an input parameter for Mandelbrot Fractal function to generate the corresponding public key. Julia Fractal function was then used to calculate the verified value based on the existing private key and the received public key. The proposed protocol was designed to be resistant against attacks. Fractal based zero-knowledge protocol was an attractive alternative to the traditional number theory zero-knowledge protocol.