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构建万物可信互联的基石，带你深度剖析区块链跨链的关键技术，满满是干货！

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【摘要】什么是区块链，相信你一定有所了解，那么你是否了解区块链跨链技术呢？本文将从区块链跨链技术的起源发展、相关名词、关键技术和模型实现几个方面进行深度剖析，干货满满！ 1．区块链跨链技术诞生背景及发展历程 1.1 什么是跨链？区块链技术经过10来年演进，已经被认为是可以参与未来可信社会构建的重要基础设施。但是现实的社会中包括许多行业和不同的经济领域。把整个现实世界中的各个行业都套用区块链是不现实的，也是不合适的。不同行业、不同经济领域的商品可以通过市场实现价值交换。每个区块链系统都是一个独立的价值经济体系。区块链跨链技术是连接独立区块链的枢纽，承载着不同价值体系的区块链之间的交换功能。价格是交换货物的前提，价格由商品本身的价值决定，受供需关系的影响，供需关系又建立在市场之上。为了实现不同区块链上的价值交换，区块链通过跨链为每个独立区块链中的价值交易市场提供跨链契约服务。每个区块链是一个独立的账本，两个不同的区块链对应两个不同的独立账本，两个账本之间没有关联关系。跨链这个技术，打通不同账本之间的障碍，允许价值跨越不同区块链进行流转。本质上，价值不能在账间转移。但是对于一个特定的用户来说，一个区块链中存储的价值可以转化为另一个区块链价值，从而实现了价值的循环。 1.2 诞生的背景及发展历程随着2008年比特币诞生以来，区块链技术已经有了非常广泛的发展

What Options Are There To Protect Database Passwords In Corda?

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问题 The Corda database password is stored in the node.conf in plain text by default: https://docs.corda.net/head/node-database.html What options are available to avoid this? e.g. can you use jasypt or store the value in an environment variable or a cloud vault system? Are there samples/examples available? 回答1: it is possible to override node.conf settings using Environment variables or JVM arguments, see here for more info: https://docs.corda.net/corda-configuration-file.html#overriding-values

Is Corda support state deletion scenario?

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问题 Is corda support state deletion scenario when don't need to use some state (in both dev/prod) Because I face exception when start node like "class not found exception", It's happen when I delete state class in project and use same old persistence file. I think it because of state class already insert in VAULT_STATES and it can't find that class when start node. I expect to have some method that provide state deletion. More info In Dev side I delete persistence file and of course it's work,

Is Corda support state deletion scenario?

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Cordapp tutorial crashing in a Fedora VirtualBox Machine

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问题 I have downloaded the Cordapp example provided in the Corda website. I follow all the steps (to run it from the console) in https://docs.corda.net/tutorial-cordapp.html without any problem until "Running the example CorDapp". Here i get to errors one way or another. First, when running workflows-kotlin/build/nodes/runnodes one or more of the nodes would not start. I was using a virtual machine with 2 cores and 4GB of RAM. Eventually, i noticed it seemed to be an issue with the RAM, so i

Corda: Gathering inputs from other parties in the network

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问题 In the tutorial, it is mentioned that a node can ask the other party to query its vault and give the required results. Is there an API that can be used to integrate this logic in the flow? Also, is it possible to ask our counter parties to gather inputs from their counter parties and return the cumulative results. Please share the example code, if any. Thanks. 回答1: There is no specialised API. You just use the standard FlowSession.send / FlowSession.receive / FlowSession.sendAndReceive calls.

Corda 3.1 - discovering which nodes are down and not operating

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问题 I have a question regarding Corda 3.1 and using the network map for the purpose of seeing if node is up - is it generally a good idea to use it for that ? From these notes https://docs.corda.net/network-map.html#http-network-map-protocol as there is a polling of the network map participants data (in case that our cached data expired) it should be technically possible to do that. Could you see any drawbacks of implementing this in that way ? If the node is configured with the

Searching the chain can i find if something has been consumed and what it was consumed by?

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问题 I am trying to pass out information to a node but that node may not have been on the network when it was initially sent out. So to work around this I am using transaction references, the transaction uses "addReferenceState" to reference previous states, and then the service hub to have the ability to recursively run back through the information. So I have this method that's all fine and works. private fun findInChain(infoState: StateAndRef<InfoState>): StateAndRef<InfoState> { val stx =

How to pass in a list of Partys for invocation of a flow from the Node shell

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问题 How to pass in a list of Partys for invocation of a flow from the Node shell? I had tried multiple ways such as passing in as a string (with multiple ways). Do i need to pass in a Json? or what is the format? 回答1: thanks for your question. The syntax for passing in lists of elements in the Corda CRaSH shell is: flow start fabFlow parties: ["party1", "party2"] The syntax for creating complicated objects can be found here but in essence is just a simple wrapping with curly braces to provide

Corda: Can we develop Dapps that will be run by IIS webserver to talk to Corda platform?

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问题 We have used "Yo!CorDapp" example (https://github.com/corda/spring-observable-stream) to build a POC. In this POC, can we replace angular by .NET for frontend and use IIS webserver in place of springboot webserver to talk to Corda platform? Thanks 回答1: You can use any front-end technology you want. As of Corda 3, your backend must be JVM-based, for two reasons: You need to load various flow, state and other class definitions onto the classpath to pass as arguments to flows, retrieve objects