Claims¶

Claims are the smallest self contained piece of information inside Userfeeds Platform. All claims are cryptographically signed or have reference to their cryptographic origin (eg. transaction on blockchain)

Structure¶

Overview¶

{
  "context": "CONTEXT",
  "type": ["TYPEA", "TYPEB", "..."],
  "claim": {
    "target": "TARGET",
    "additional": "fields",
    "go": ["here", "..."]
  },
  "credits": [
    {
      "type": "interface",
      "value": "INTERFACE IDENTIFIER"
    }
  ],
  "signature": {
    "type": "TYPE",
    "creator": "CREATOR",
    "signatureValue": "SIGNATURE"
  }
}

`context`¶

optional

Context field is used to denote destination of given claim. It can be interpreted as name of any topic/thing that people might want to share information about. Usually it will have something to do with blockchain space (but it doesn’t have to). For example if you would like to share some information to all people interested in Ethereum blockchain you will send claim with ethereum as context.

Other examples of contexts might be:

ethereum

ethereumclassic

bitcoin

ethereum:0x4564567890abcdef....abc

ethereumclassic:0x4564567890abcdef....abc

myspecialcontext

companyx

companyx:departmenty

ethereum:0x123....456 context identifiers are interpreted as object 0x123....456 on ethereum and usually will be used to share information about contracts/addresses on given blockchain.

Special contexts starting with userfeeds: are technical context and have special meaning in Userfeeds Platform. eg. userfeeds:pairing will create special PAIRED relationship allowing one to connect their cryptocurrency holdings with additional public key that will only be used to sign claims.

`type`¶

optional

Type describes additional data present in claim object.

Example can be labels type, with this type claim object needs to have labels key with array of values.

Description of all supported types can be found at Types

`claim`¶

This key is used to store user provided information and it is mandatory for all claims. claim object will always have target key and additional fields depending on type array.

`target`¶

target value identifies target object that user wants to share or tag with additional information.

Some examples of proper target values:

http://some.url/path/

text:base64:base64encodedtext

ipfs:somehash

ipdb:somehash

claim:claimsignaturehash

mediachain:somehash

isbn:0451450523

isan:0000-0000-9E59-0000-O-0000-0000-2

btih:c12fe1c06bba254a9dc9f519b335aa7c1367a88a

ethereum:0x4564567890abcdef...abc

bitcoin:0x4afebcdef...123

Additional fields¶

Depending on type array additional keys might be present in claim object. See Types for supported types.

`signature`¶

This field is generated to denote ownership of claim and can be cryptographic signature or a pointer to cryptographically secure origin of claim.

`type`¶

Describes what type of signature we are dealing with. It could be ecdsa.secp256r1 for elliptic curve signature or ethereum.transaction for claim origination from Ethereum blockchain.

Supported Signature Types¶

ecdsa.prime192v1: In python: ecdsa.NIST192p
ecdsa.secp256r1 / ecdsa.prime256v1: In python: ecdsa.NIST256p
ecdsa.secp224r1: In python: ecdsa.NIST224p
ecdsa.secp384r1: In python: ecdsa.NIST384p
ecdsa.secp521r1: In python: ecdsa.NIST521p
ecdsa.secp256k1: In python: ecdsa.SECP256k1
ethereum.transaction: Claims posted on ethereum blockchain will be verified by comparing blockchain content with claim content.

`creator`¶

This identifies public key or address that signed claim.

Format: identifier

hex:04861127b14bf0036e...ef7127b114988057

rinkeby:0x1234567890abcdef...1456

ethereum:0x1235...145

bitcoin:0x123456...1234

`signatureValue`¶

This key holds raw signature value as produced by signing algorithm, or it can be transaction hash or any valid identifier of externally verifiable origin of claim.

Types¶

Basic¶

Basic claim:

{
  "claim": {
    "target": "http://some.url/path/"
  },
  "context": "ethereum:0x4564567890abcdef....abc",
  "signature": {
    "creator": "94d1aa6655d931294d524cf52b0df866976f89774bac38a730cf20e2d51dd24d34efc2bbb4d5bba91a7a6582511491dde1803dcdf7fd55550cf3132aae16077a",
    "signatureValue": "304402203dac2176721d7e05cd8c580a27a504b64b0a8ee171b18a07630201cbed979ac7022013faf8735f90b957ca4656efb17349856ac22894aab553db136b7dfc2b03ede4",
    "type": "ecdsa.prime256v1"
  }
}

With acknowledgment of interface from which claim was created:

{
  "claim": {
    "target": "http://some.url/path/"
  },
  "context": "ethereum:0x4564567890abcdef....abc",
  "credits": [
    {
      "type": "interface",
      "value": "http://blog.example.com/path/"
    }
  ],
  "signature": {
    "creator": "0df1d4915347bcae90a0696c9efd6300e33b610d31130c3049d329fa61af138de7a7ee55f99057fd8d39c4664be9f1c34361c237433b34c8f523c5858f9fb9a0",
    "signatureValue": "304502206c243684007c9e412612b5d1a371b20eb146652e4b149bb1fc0e6da437e7f728022100b8c77983949feac478de449751587be82d5b37ff30b257da04f2352aab5f8793",
    "type": "ecdsa.prime256v1"
  }
}

`link`¶

Additional keys:

title string

summary string

{
  "claim": {
    "summary": "summary",
    "target": "http://some.url/path/",
    "title": "title"
  },
  "context": "rinkeby:0xfe5da6ae3f65e7d5ce29121a9f5872ffd83b45e6",
  "credits": [
    {
      "type": "interface",
      "value": "http://blog.example.com/path/"
    }
  ],
  "signature": {
    "creator": "ffc8c2f39e8a302bf9ca37b06fa9014f0cd3c85900c3d8b771f31a91ce33c050948faedad14d73a4f6c41f5937c3a010b5af24055092c136b7a667fee2249f87",
    "signatureValue": "304602210093c55c30be1868de005def995aefb391d7ff20f235457b37a01e6921427701f80221008e5fc2afc2c9124660a57f9a2c9f4be1187afe3bc4b3c67a30e9a4c52747f4f7",
    "type": "ecdsa.prime256v1"
  },
  "type": [
    "link"
  ]
}

`labels`¶

Additional keys:

labels array of string

{
  "claim": {
    "labels": [
      "Good",
      "Book",
      "Cats"
    ],
    "target": "http://some.url/path/"
  },
  "context": "rinkeby:0xfe5da6ae3f65e7d5ce29121a9f5872ffd83b45e6",
  "signature": {
    "creator": "de9965ce03cf6f960a7efe423633409a0052ad8f9f2100e27026ad94551d4d69058c0a263dbd0cacf999ca3e97ddcc0afae5051e91dc42c4ca008e4c7c5c0ddb",
    "signatureValue": "3044022069457927f1fc06b26467a7cc93c99085efea4d8811c6979ffab9ba2196be5ad702201587d3f88d2e9058d6ce48708ddf8713b07017a311ce713b566a1829ea516e41",
    "type": "ecdsa.prime256v1"
  },
  "type": [
    "labels"
  ]
}

Transports¶

HTTP¶

You can send signed claims through Userfeeds Platform HTTP Gateway

Properties:

In-transport secrecy: the claim cannot be sniffed on transport thanks to HTTPS connection and will only be available to outside world after it’s incorporated into Userfeeds Platform through rankings APIs and database dumps.
Independent distribution: the claim exists only inside Userfeeds Platform database and will be distributed with Userfeeds Platform database dumps.

Example of posting claim directly to Userfeeds Platform through HTTP transport

$ curl \
  -X POST https://api.userfeeds.io/storage/ \
  -H "Content-Type: application/json" \
  -H "Authorization: 59049c8fdfed920001508e2a03414df648e34ea665f544a17d5c113b" \
  -d '{"claim":{"target":"http://some.url/path/"},"context":"ethereum:0x4564567890abcdef....abc","signature":{"creator":"82fb68fc14719b94b36e99e588c9988458ca187d4791463164285bb064458232c4bb5bb638158096f4ed957e275e2e1576d1b24cca81ceb3a53cd7493ae88474","signatureValue":"c675d123fb1e99ffe59e7626c655806ebe47ec1ca4100b953029731159c2e14f4461e2ebf7f43a071b847b57cbcbd66bd8fa9451a5e27c4db4bbaec3cdd16b02","type":"ecdsa.prime256v1"}}'

Ethereum Transaction¶

You can send claim through Ethereum Blockchain transaction.

Note

Userfeeds Platform does not yet monitor every transaction for potential claims

To send a claim through transaction you need to call special contracts that are monitored by Userfeeds Platform.

Properties:

In-transport secrecy: The claim is available from the moment it’s distributed through Ethereum network and can be sniffed before it reaches desired ranking.
Independent distribution: The claim will be a part of Etherum Blockchain and will be available from all copies of the blockchain.

Contracts¶

With value transfer

Code

pragma solidity ^0.4.11;

contract Userfeeds {

    event Claim(address sender, address userfeed, string data);

    function post(address userfeed, string data) payable {
        userfeed.transfer(msg.value);
        Claim(msg.sender, userfeed, data);
    }
}

ABI

[
  {
    "constant":false,
    "inputs":[
      { "name":"userfeed", "type":"address" },
      { "name":"data", "type":"string" }
    ],
    "name":"post",
    "outputs":[],
    "payable":true,
    "type":"function"
  },
  {
    "anonymous":false,
    "inputs":[
      { "indexed":false, "name":"sender", "type":"address" },
      { "indexed":false, "name":"userfeed", "type":"address" },
      { "indexed":false, "name":"data", "type":"string" }
    ],
    "name":"Claim",
    "type":"event"
  }
]

Addresses

Mainnet: ...

Rinkeby: 0x0a48ac8263d9d79768d10cf9d7e82a19c49f0002

Ropsten: 0xa845c686a696c3d33988917c387d8ab939c66226

Kovan: 0xebe67ecee8f7a222e4451f04dca903cb2bfead7f

Without value transfer

Code

pragma solidity ^0.4.11;
contract Userfeeds {

    event Claim(address sender, string data);

    function post(string data) {
        Claim(msg.sender, data);
    }
}

ABI

[
  {
    "constant":false,
    "inputs":[
      { "name":"data", "type":"string" }
    ],
    "name":"post",
    "outputs":[],
    "payable":false,
    "type":"function"
  },
  {
    "anonymous":false,
    "inputs":[
      { "indexed":false, "name":"sender", "type":"address" },
      { "indexed":false, "name":"data", "type":"string" }
    ],
    "name":"Claim",
    "type":"event"
  }
]

Addresses

Mainnet: ...

Rinkeby: 0x09dcdf34e0c28b106fdfe51009cb71ae92bf8bbc

Ropsten: 0x5c3fe6b94b57c1e294000403340f12f083e71b83

Kovan: 0x7d9ab4747413f470306a9fb1dab4092cfbc3355e

Whisper Protocol¶

TODO: Direct message TODO: Broadcast

IPDB (BigchainDB)¶

TODO

Claims¶

Structure¶

Overview¶

context¶

type¶

claim¶

target¶

Additional fields¶

signature¶

type¶

Supported Signature Types¶

creator¶

signatureValue¶

Types¶

Basic¶

link¶

labels¶

Transports¶

HTTP¶

Ethereum Transaction¶

Contracts¶

Whisper Protocol¶

IPDB (BigchainDB)¶

`context`¶

`type`¶

`claim`¶

`target`¶

`signature`¶

`type`¶

`creator`¶

`signatureValue`¶

`link`¶

`labels`¶