Pol Alemany, Ricard Vilalta, Raül Muñoz, Ramon Casellas · 5 authors
Data center (DC) interconnection allows us to have optical transmissions between DCs directly connected to optical networks, avoiding the use of a packet-based infrastructure. Thanks to the use of next-generation pluggable coherent optics, it is possible to create connectivity services (CSs) across multiple optical transport domains. In this multi-domain CS scenario, cloud operators and transport operators have to work together in the most dynamic way possible. To do so, they need a common place (i.e., a market) where the transport operators may expose their available optical resources and the cloud operators request (e.g., rent) them to be used in order to create end-to-end (E2E) CSs between DCs. Having multiple transport operators exposing their resource information in a common place requires a set of common rules (i.e., how much of the topology to show) to create E2E CSs requested between cloud operators. This paper makes use of the blockchain technology to present a blockchain-based extension for the software-defined network (SDN) architecture to allow each optical transport operator domain to become a peer in a blockchain network. In there, each peer follows the same rules and shares the same exact level of topology information by using a specific abstraction model to map the optical domain resources. This paper uses a set of three different abstraction models to validate their behavior on a blockchain system when managing multiple domain resources and the deployment of CSs across these domains. To do so, an experimental comparison on how the different abstraction models affect the performance of the blockchain system is presented.
We propose LightHash , the first feasible photonic cryptographic hash function for blockchain technology using programmable photonic networks. We experimentally evaluate LightHash and assess whether photonic circuits can outperform digital competitors in latency and energy efficiency.
Jingchi Li, Shaohua An, Honglin Ji, Xingfeng Li · 6 authors
For high-capacity and short-reach applications, carrier-assisted differential detection (CADD) has been proposed, in which the optical field of a complex-valued double sideband (DSB) signal is reconstructed without using a sharp-edge optical bandpass filter or local oscillator laser. The CADD receiver features a transfer function with periodical nulls in the frequency domain, while the signal-signal beat interference (SSBI) is severely amplified around the frequency nulls of the transfer function. Since the null magnitude at the zero frequency is inevitable, a guard band is required between the carrier and the signal, leading to a higher receiver bandwidth and implementation cost. To reduce the needed guard band, we propose a parallel dual delay-based CADD (PDD-CADD), in which an additional delay is placed parallel to the original delay in the conventional CADD. By this means, the modified transfer function has a sharper roll-off edge around the zero frequency. Consequently, the requirement on the guard band can be relaxed, which maximizes the bandwidth utilization of the system. The parallel delay is first optimized through numerical simulation. We then perform a proof-of-concept experiment to transmit a 100-Gb/s orthogonal frequency division multiplexing (OFDM) 16-ary quadrature amplitude modulation (16-QAM) signal over an 80-km single-mode fiber (SMF). After the fiber transmission, the proposed PDD-CADD can reduce the required guard band from 3 to about 1.2 GHz compared with the single delay-based conventional CADD. To our best knowledge, for the direct detection of a single polarization complex-valued DSB signal without using a sharp-roll-off optical filter, we achieve a record electrical spectral efficiency of 5.9 b/s/Hz.
Bitcoin's throughput is far lower than those of centralized systems such as Visa and PayPal. To handle a comparable number of transactions, Bitcoin's throughput must be improved, which will require a reduction in the block propagation time. Relay networks have attracted attention as a method to improve throughput. However, the nature and strength of the effects of relay networks are not yet clear. In particular, the effects on individual nodes have received little attention. Thus, this study aims to investigate the effects of relay networks on the Bitcoin network and its nodes under the current network state in approximately 2019. We simulate a relay network under the current network state because simulation is virtually the only way to obtain data for all nodes. A major contribution of this study is that it is the first to investigate the relay network effect on the 90th percentile of block propagation time. Moreover, this study shows that relay networks benefit not only the system but also the nodes utilizing them. The utilizing nodes' blocks were more than six times more likely to be approved as valid blocks when nonutilizing and utilizing nodes generated blocks simultaneously. This finding can motivate the use of nodes in relay networks.
2 source records
Blockchain Technology Applications and Security
Caching and Content Delivery
Advanced Steganography and Watermarking Techniques
Mohammed Amine Togou, Ting Bi, Kapal Dev, Kevin McDonnell · 7 authors
5G technology is expected to enable a plethora of new applications with distinct requirements. Provisioning resources to accommodate such applications implies having a flexible network infrastructure that can be tailored to the specific needs of each application. This can be achieved through network slicing. Still, several applications might request network slices, but their request may not be fulfilled due to lack of resources or lack of coverage and provisioning such resources is a cumbersome task. This paper describes an architecture that facilitates the dynamic leasing of resources among network operators to support cross-domain services. The cornerstone of this architecture is a brokering layer, called DBB, that relies on a blockchain-based bidding system to request resources and evaluate resource provisioning offers. The paper also presents a simulation-based use case scenario that illustrates the need for DBB and which was used to evaluate the performance of the proposed architecture.
Current permissionless cryptocurrencies such as Bitcoin suffer from a limited transaction rate and slow confirmation time, which hinders further adoption. Payment channels are one of the most promising solutions to address these problems, as they allow the parties of the channel to perform arbitrarily many payments in a peer-to-peer fashion while uploading only two transactions on the blockchain. This concept has been generalized into payment channel networks where a path of payment channels is used to settle the payment between two users that might not share a direct channel between them. However, this approach requires the active involvement of each user in the path, making the system less reliable (they might be offline), more expensive (they charge fees per payment), and slower (intermediaries need to be actively involved in the payment). To mitigate this issue, recent work has introduced the concept of virtual channels (IEEE S&P’19), which involve intermediaries only in the initial creation of a bridge between payer and payee, who can later on independently perform arbitrarily many off-chain transactions. Unfortunately, existing constructions are only available for Ethereum, as they rely on its account model and Turing-complete scripting language. The realization of virtual channels in other blockchain technologies with limited scripting capabilities, like Bitcoin, was so far considered an open challenge.In this work, we present the first virtual channel protocols that are built on the UTXO-model and require a scripting language supporting only a digital signature scheme and a timelock functionality, being thus backward compatible with virtually every cryptocurrency, including Bitcoin. We formalize the security properties of virtual channels as an ideal functionality in the Universal Composability framework and prove that our protocol constitutes a secure realization thereof. We have prototyped and evaluated our protocol on the Bitcoin blockchain, demonstrating its efficiency: for n sequential payments, they require an off-chain exchange of 9+2n transactions or a total of 3524+695n bytes, with no on-chain footprint in the optimistic case. This is a substantial improvement compared to routing payments in a payment channel network, which requires 8n transactions with a total of 3026n bytes to be exchanged.
Shifeng Ding, Gangxiang Shen, Kevin X. Pan, Sanjay K. Bose · 6 authors
In communication networks, network virtualization can usually provide better capacity utilization and quality of service (QoS) than what can be achieved otherwise. Under this operation, once the capacity of a virtual optical network (VON) is allocated, it will be static for a certain period, for example, a service contract period. However, in reality, the actual traffic demand of a VON always fluctuates, which would lead to a mismatch between the capacity assigned and the actual traffic demand carried. This mismatch would further cause degradation of provisioned network services and inefficiency in assigned network capacity. To overcome this issue, we propose a new scheme, called spectrum trading (ST), to trade spectrum resources between VONs in the context of an elastic optical network (EON). The key idea is to allow different VONs to trade their spectrum resources according to their actual capacity requirement at different time instants. A VON with unused spectra can trade away its unused spectra to other VONs that are short of spectrum resources at that time. in exchange, it is rewarded with some credit for its contribution to the ST community, which it can then use later to obtain extra capacity, if needed. The trust-worthiness of the trading records between the VONs is ensured in a distributed fashion through a blockchain- assisted ledger that is updated whenever a new trade occurs. A software-defined control plane is also developed to enable spectrum trading with the support of the blockchain-assisted ledger. The performance of the ST scheme is evaluated and compared with the scenario without such trading. Results show that the proposed ST scheme is efficient in improving the QoS of each VON and significantly improves overall network capacity utilization.
The past decade has witnessed an explosive growth in cryptocurrencies, but the blockchain-based cryptocurrencies have also raised many concerns, among which a crucial one is the scalability issue. Suffering from the large overhead of global consensus and security assurance, even the leading cryptocurrencies can only handle up to tens of transactions per second, which largely limits their applications in real-world scenarios. Among many proposals to improve the cryptocurrency scalability, one of the most promising and mature solutions is the payment channel network (PCN), which offers the off-chain settlement of transactions with minimal involvement of expensive blockchain operations. However, transaction failures may occur due to external attacks or unexpected conditions, e.g., an uncooperative user becoming unresponsive. In this paper, we present a distributed robust payment routing protocol RobustPay to resist transaction failures, which achieves robustness, efficiency and distributedness. Moreover, we modify the original HTLC protocol and adapt it to the robust payment routing protocol.
Yoshitomi Eduardo Maehara Aliaga, Diego Fernandes Gonçalves Martins, Marco Aurélio Amaral Henriques
Neste trabalho apresentamos uma proposta mecanismo de consenso para blockchain baseado em PoS, que viabiliza a participação de usuários de uma maneira mais justa. Através da utilização de tempo discreto o protocolo utiliza rodadas, onde apenas participantes que passaram no desafio da rodada possam gerar o bloco. O protocolo garante uma participação mais igualitária pois não é possível gerar o bloco antes da próxima rodada esperada.
The inevitable trend to develop 5G and beyond puts higher requirements on the intelligence of optical networks. In the operation of an optical network, many processes can take advantage of emerging technologies for effective optimization, such as resource allocation, fault operation, traffic classification and prediction and also security convincement.Artificial intelligence (AI) is a method which establishes digital logical topologies following the structure of biological neural network to reproduce its analysis and learning process. Besides, blockchain is also a secure, decentralized architecture that supports the trustworthiness of distributed communications and storage. These two technologies are considered to have great potential in optimizing the intelligent optical network in different aspects.In this paper, we will demonstrate some possible approaches of how AI and blockchain can separately be integrated with optical network to improve its performance.
Neural Networks and Reservoir Computing
Optical Network Technologies
Spectroscopy Techniques in Biomedical and Chemical Research
Software defined optical networking (SDON) is a critical technology for the next generation network with the advantages of programmable control and etc. As one of the key issues of SDON, the security of control plane has also received extensive attention, especially in certain network scenarios with high security requirement. Due to the existence of vulnerabilities and heavy overhead, the existing firewalls and distributed control technologies cannot solve the control plane security problem well. In this paper, we propose a distributed control architecture for SDON using the blockchain technique (BlockCtrl). The proposed BlockCtrl model introduces the advantages of blockchain into SDON to achieve a high-efficiency fault tolerant control. We have evaluated the performance of our proposed architecture and compared it to the existing models with respect to various metrics including processing rate, recovery latency and etc. The numerical results show that the BlockCtrl is capable of attacks detection and fault tolerant control in SDON with high performance on resource utilization and service correlation.
Vincent Messié, Gaël Fromentoux, Xavier Marjou, Nathalie Labidurie Omnes
In this article, we highlight a novel solution for densifying 5G access networks. Taking benefits from local actors and prosumers, our proposal allows offering a better connectivity to end-users in a model involving network operators and a crowd of local actors. We show that building a multi-actors and densified access network infrastructure has become possible in a distributed way. Incumbent actors with a large footprint act as trusted partners securing the infrastructure and providing guarantees, while the crowd of local actors deploys multiple access points and are rewarded for their contribution. Rewarding is possible thanks to a distributed Bandwidth & Identity ledger along with a Proof of Bandwidth (PoB) mechanism. This article presents the main principles of this new connectivity platform, BALAdIN (Bandwidth Ledger AccountIng Networks), which relies on a consortium blockchain with access control mechanisms removing communitarian Wifi and ad hoc networks drawbacks. Indeed, combining distributed ledgers and edge networks allows local actors to cooperate with trusted parties, which leverages the full potential of multi-actors access networks.
We present a distributed blockchain-based trusted control (BlockTC) architecture with multi-controller credible routing for software defined data center optical network in 5G and beyond. The feasibility and efficiency of architecture are verified on our testbed.
This paper presents a blockchain-based high-efficiency security strategy with blockchain ledger-based recovery algorithm for software-defined optical networks. Numerical results show the proposed strategy has less recovery latency and superior network performances.
The goal of this research is to estimate the data propagation time on the Bitcoin network. Using network coordinates, we estimate the communication latency between computers. Such latency estimation contributes future optimization of data propagation. In this research, we report an experiment on computing the network coordinates. In the current Bitcoin network, it is very difficult to acquire internode delay because the network topology is not available. In this study, we calculate the delay based on our topology estimation and describe the effectiveness of the network coordinates using various topology estimation parameters.
Bitcoin has a low transaction throughput. In order to allow for an increase of this throughput without increasing orphan blocks, decreasing the block propagation time is important. One of the techniques to improve its block propagation time is to utilize relay networks. However, the effects of utilizing relay networks is not apparent. Existing studies and measurements on relay networks have not focused on the effect of relay networks on the individual miners. Moreover, the relation between the degree of the effect and relay network utilization rate is unknown. Herein, we performed simulations while finely changing the proportion of nodes utilizing a relay network. Moreover we quantitatively evaluated the effect of relay networks on the entire Bitcoin network and individual miners. Results show that the propagation time decrease to approximately 77% of the original value if the utilization rate is set to 3%. This rate is close to the actual utilization rate of relay network "Falcon". We also found that the probability of blocks created by utilizing nodes to become orphan blocks is surprisingly smaller than that of the non-utilizing nodes. Even in the worst case, the value of utilizing nodes is 15% of the value of non-utilizing nodes.
We first present a blockchain-based trusted cloud radio over optical fiber network architecture (BlockONet) with anonymous access identification for future 5G fronthaul. The feasibility and efficiency of the architecture are experimentally verified on our testbed.
Suhaidi Hassan, Yousef Fazea, Adib Habbal, Huda Ibrahim
The blockchain is a distributed ledger shared among computers around the world that allowing anyone to transact and do business with each other. Once a new block is created, ledger's transactions are updated and synchronized. Hence, the speed of information propagation in order to minimize the time taken by a node to verify a block before announcing it to the network is very significant that should be leveraged by the enabling technologies. However, due to the huge of data capacity needed, mode division multiplexing (MDM) is a promising approach to provide an additional level of freedom through propagating different channels in multimode fiber (MMF). Nevertheless, mode coupling is considered as the primary bandwidth impairment of MMF due to the mode's random perturbation. This paper investigates the potential of mode spacing in conjunction with a feed-forward equalizer on twisted Laguerre-Gaussian (LG) MDM. Free error transmission of 40Gbit/s over MMF is achieved. The bit-error-rate and eye diagram have been used as a measurement metrics.
Cloud radio access network (C-RAN) interconnects thousands of terminal devices to support the services of Internet of Things (IoT) in 5G area. However, centralized access authentication of each terminal has been performed in mobile core network which causes an extremely high operating and capital expenditure of network. Traditional C-RAN cannot provide an authentic mechanism to guarantee the security of services and creditability of device and resource accessing with low network cost. We first propose a blockchain-based trusted authentication (BTA) architecture for 5G with blockchain-based anonymous access (BAA) scheme in cloud radio over fiber network. The feasibility and efficiency are verified on enhanced SDN testbed to enable blockchain as a service.
In many technical systems, such as smart grids, the central issue is to enable multiple devices to solve a resource allocation problem. Because centralized solutions usually struggle with an increasing number of agents, regio-central or completely decentralized mechanisms, which solve the problem in a cooperative manner, are of utmost interest in large-scale systems. In this paper, we present a coalition-based algorithm that allows a multi-agent system to cooperatively solve a single-resource allocation problem. Our approach uses self-organization to dynamically identify groups of agents whose decisions have to be coordinated, while optimistically refraining from coordinating the actions between these coalitions. The basic idea of our algorithm is inspired by the way pressure compensates in gas or fluid pipeline systems. It therefore operates on the basis of an overlay network, i.e., a graph, that defines a topology of possible resource flows as well as resistances in the form of costs of transferring a resource from one agent to another. Throughout this paper, the problem of compensating for imbalances between energy production and consumption in autonomous power management systems serves to illustrate our algorithm and results.
We present a general framework for constructing non-interactive universally composable (UC) commitment schemes that are secure against adaptive adversaries in the non-erasure setting under a single re-usable common reference string. Previously, such “fully-equipped ” UC commitment schemes are only known in [8, 9], with an unavoidable overhead of O(κ) in the sense of communication and computational complexities; meaning that to commit λ bits, the communication and computational costs require O(λκ), where κ denotes the security parameter. Efficient construction of a fully-equipped UC commitment scheme was a long-standing open problem. We introduce a cryptographic primitive, called all-but-many encryptions (ABMEs), and prove that it is a translation of fully-equipped UC commitment in the primitive level. We then construct ABMEs from cryptographic primitives that we call a probabilistic pseudo random function family and extractable sigma protocols – the former is a probabilistic version of a pseudo random function family and the latter is a special kind of sigma (i.e., canonical 3-round public-coin HVSZK) protocols with some extractability. We provide fully-equipped UC commitment schemes from ABMEs under DDH and DCR-based assumptions, respectively. In particular, the DCR-based scheme is the first fully-equipped UC commitment scheme with optimal expansion factor Ω(1); to commit κ bits, the communication and computational costs are Ω(κ). We further construct a fully-equipped UC commitment scheme from a general assumption (in which trap-door permutations exist), which is far more efficient than the previous construction [9], because, unlike [9], our construction does not require non-interactive zero-knowledge proof systems. 1