A Hardware-Based Caching System on FPGA NIC for Blockchain

Abstract

Engineers and researchers have recently paid attention to Blockchain. Blockchain is a fault-tolerant distributed ledger without administrators. Blockchain is originally derived from cryptocurrency, but it is possible to be applied to other industries. Transferring digital asset is called a transaction. Blockchain holds all transactions, so the total amount of Blockchain data will increase as time proceeds. On the other hand, the number of Internet of Things (IoT) products has been increasing. It is difficult for IoT products to hold all Blockchain data because of their storage capacity. Therefore, they access Blockchain data via servers that have Blockchain data. However, if a lot of IoT products access Blockchain network via servers, server overloads will occur. Thus, it is useful to reduce workloads and improve throughput. In this paper, we propose a caching technique using a Field Programmable Gate Array-based (FPGA) Network Interface Card (NIC) which possesses four 10Gigabit Ethernet (10GbE) interfaces. The proposed system can reduce server overloads, because the FPGA NIC instead of the server responds to requests from IoT products if cache hits. We implemented the proposed hardware cache to achieve high throughput on NetFPGA-10G board. We counted the number of requests that the server or the FPGA NIC processed as an evaluation. As a result, the throughput improved by on average 1.97 times when hitting the cache.

Analysis of Blockchain Solutions for IoT: A Systematic Literature Review

“…The range of data size varies among all the studies [8], [11], [23], [30], [33], [35], [36]. The largest data size per transaction reported was 0.022MB while the smallest data size per transaction was 0.00007MB.…”

“…Six studies [10], [12], [20], [25], [27], [35] leveraged blockchain to solve the integrity issues such as integrity of the collected data from sensors and integrity of Things' state. There are nine studies [9], [12], [30]- [33], [36], [40], [42] that attempted to solve the limited computational capability of Things on IoT platform. For example, Things connected to the IoT network do not have the capability to carry out encoding of the collected data.…”

“…There are 16 out of 35 studies used Ethereum [8], [10]- [12], [14], [19], [20], [23], [24], [27], [32], [34], [36]- [38], [42] while four used Bitcoin network [22], [28], [30], [34]. Out from the remaining 35, four used Multichain [21], [30], [33], [39], followed by three studies that used Hyperledger [15], [31], [40] and one used Monax [33].…”

“…Twenty studies [8], [10]- [12], [14], [19]- [21], [23], [24], [27], [30], [32]- [34], [36]- [39], [42] implemented blockchain solutions that use Proof-of-Work (PoW) consensus for their IoT platform while three studies [15], [31], [40] selected to use blockchain with Byzantine-Fault Tolerance (BFT) consensus. There are one study [33] that used Proof-of-Stake (PoS) consensus and 4 studies [21], [30], [33], [39] used round robin consensus.…”

“…Out of 35 studies, 19 used blockchain as a data storage [8]- [16], [20], [29], [30], [32], [35], [36], [39]- [42], follows by [8], [18], [19], [22]- [25], [28], [34], [38] (n = 10) that used blockchain as access control mechanism. There are six studies that used blockchain as platform connector [17], [21], [23], [27], [33], [37] to interconnect between the sensors and the high computing nodes.…”