corda

Do we really need a notary that validates?

泄露秘密 提交于 2019-12-08 05:38:36
问题 At the risk of sounding naive, I ask myself "Is a validating notary necessary?", given all the issues with it - transaction and dependencies leak, exposure of state model, to name a few. The answer I hear has something to do with the potential attack where a dishonest node tries to steal someone else's asset. For example, in a legitimate transaction, partyA sold partyB some asset S subject to a Move contract. Immediately afterwards, partyA creates a self-signed transaction that transfers S

Trust and agreement between Corda nodes

心已入冬 提交于 2019-12-08 01:18:44
问题 When a single node in a consortium or a consortium as a whole runs the notary service, how can trust be established between the nodes in a consortium? How can one node trust the other node to run the notary? In the case, where the notary is a 3rd Party, how does all the nodes in the consortium come to an agreement to choose this 3rd party to run the nodes? Thank you. 回答1: It will often be the case that there is no clear node or pool of nodes that can be absolutely trusted to run a notary pool

Do we really need a notary that validates?

跟風遠走 提交于 2019-12-07 22:31:35
At the risk of sounding naive, I ask myself "Is a validating notary necessary?", given all the issues with it - transaction and dependencies leak, exposure of state model, to name a few. The answer I hear has something to do with the potential attack where a dishonest node tries to steal someone else's asset. For example, in a legitimate transaction, partyA sold partyB some asset S subject to a Move contract. Immediately afterwards, partyA creates a self-signed transaction that transfers S back to himself subject to a dummy contract in a bogus flow that does not even run the ledger transaction

Implementing schedulable states in corda [closed]

帅比萌擦擦* 提交于 2019-12-07 18:46:26
问题 Closed . This question needs to be more focused. It is not currently accepting answers. Want to improve this question? Update the question so it focuses on one problem only by editing this post. Closed 2 years ago . How do we implement schedulable state in corda? In my case i need to issue a monthly statement, so can schedulablestate be used for this? 回答1: There are a number of things you need to do. Firstly, your state object needs to implement the SchedulableState interface. It adds an

IllegalStateException Error while generating node info files

混江龙づ霸主 提交于 2019-12-07 13:02:34
问题 I am getting the following issue when I perform the gradle clean deployNodes command on AWS Ubuntu machine for Corda project: Error while generating node info files I am using Corda ENT libs. And interestingly the same corda project works on the Windows machine but fails on AWS machine. JDK 1.8.181 and gradle 4.10.2 on AWS and windows machine. It asks to check logs files but logs show nothing related to any error ... Can you please help with this issue? It's giving an exception for: if (

Is it possible to suspend a flow such that it can be resumed with an RPC-call?

本小妞迷上赌 提交于 2019-12-07 12:30:15
问题 I am trying to implement the following use-case in Corda: FlowA has been invoked on PartyA via startFlowDynamic . FlowA creates a partially signed transaction and invokes FlowB on PartyB via sendAndReceive . A human user shall now review and manually approve this transaction. Ideally FlowB should suspend after receiving the transaction. I would like to be able to query for suspended instances of FlowB via RPC, and present those (or rather some representation of the transaction therein) to the

Browse Corda database tables using H2 web interface shows synonyms errors

房东的猫 提交于 2019-12-07 10:40:53
问题 I followed the instructions at this link to browse corda database. However, I am getting below errors when I queried for tables. Error: Table "SYNONYMS" not found; SQL statement: SELECT TABLE_CAT, TABLE_SCHEM, TABLE_NAME, TABLE_TYPE, REMARKS, TYPE_CAT, TYPE_SCHEM, TYPE_NAME, SELF_REFERENCING_COL_NAME, REF_GENERATION, SQL FROM (SELECT SYNONYM_CATALOG TABLE_CAT, SYNONYM_SCHEMA TABLE_SCHEM, SYNONYM_NAME as TABLE_NAME, TYPE_NAME AS TABLE_TYPE, REMARKS, TYPE_NAME TYPE_CAT, TYPE_NAME TYPE_SCHEM,

怎么入门区块链?区块链的门槛高吗?

左心房为你撑大大i 提交于 2019-12-07 09:47:45
一、区块链产生背景 互联网上的贸易,几乎都需要借助可信赖的第三方信用机构来处理电子支付信息。这类系统内生性地受制于“基于信用的模式”。 区块链技术是构建比特币区块链网络与交易信息加密传输的基础技术。其中基于密码学原理的特性,使得任何达成一致协议的双方直接支付,从而不需要第三方机构的参与。 二、区块链特点 分布式数据库并非新发明,市场上早有此类产品。但是,区块链有一个革命性特点。 区块链没有管理员,它是彻底无中心的。其他的数据库都有管理员,但是区块链没有。如果有人想对区块链添加审核,也实现不了,因为它的设计目标就是防止出现居于中心地位的管理当局。 正是因为无法管理,区块链才能做到无法被控制。否则一旦大公司大集团控制了管理权,他们就会控制整个平台,其他使用者就都必须听命于他们了。 三、入门区块链 1.区块链底层技术,如共识算法, 侧链技术, 密码学知识等, 理解PKI基本知识和原理; 2.研究以太坊技术,了解ERC20,能够自行开发DAPP; 3.熟悉Hyperledger Fabric 1.0架构,了解其业务流程和设计理念, 相关应用 4.了解比特币、以太坊,Ripple,Corda, IOTA, Skycoin等业界热门的区块链设计特点及相关应用; 5.具备Fabric,以太坊,Ripple,Corda等区块链底层研发的基础能力。 四、区块链的门槛 区块链对于普通人而言

How can I configure security per node in Corda using Gradle?

假装没事ソ 提交于 2019-12-06 14:57:33
问题 I want to add the security property to my node configuration using Gradle. I'm trying to do something like the below: node { name "O=Bank_A,L=New York,C=US" p2pPort 10005 rpcSettings { address("localhost:10006") adminAddress("localhost:10046") } h2Port 9005 cordapps = [ "$project.group:bank-abc:$project.version", "$project.group:shared-contracts-states:$project.version", "$corda_release_group:corda-finance:$corda_release_version" ] security = { authService = { dataSource = { type = "DB"

Is there a way to add more information to a node, except the mandatory ones?

坚强是说给别人听的谎言 提交于 2019-12-06 14:19:46
I want to add more node information to a network node. Is it possible to share more data besides what's in the node configuration file? Maybe some custom fields, like an encoded logo image or stuff like that. Thanks Yes you can. Inside your module under src folder add a file called config.conf . Add your values inside of it in the following format: key1="string_value" key2=number_value Inside build.gradle go to the part where you define your nodes, let's say your module name is "my_module"; do this: cordapp (project(':my_module')) { config project.file("src/config.conf") } Now when you run