Whitepaper: https://0xcert.org/whitepaper.pdf
- A unique, one-of-a-kind asset.
- A digital asset like a collectible, a document or a thing.
- Follows ERC721 specification.
- Non-fungible token in 0xcert protocol.
- Used for storing a proof of a digital asset.
- Xcert implements ERC721 specification.
- Xcert implements ERC721Metadata specification.
- Xcert implements ERC165.
- Xcert extends the non-fungible token standard and enables storing a digital asset proof.
- Xcert supports proof revisions (history chain).
- A JSON data object representing assets from the real-world as digital assets.
- Described by JSON Schema.
- Following vocabulary of schema.org for easy translation into JSON-LD.
- Uses DID URI for dependent assets formatted as
did:xcert:{contract-address}/{token-id}/{revision}
.
Example:
{
"expires": "2020-01-01",
"name": "Web developer",
"issuer": "did:xcert:0xff0asdjd38d8s8a8g73n2n5n12m3n1n5b2/100/0",
"owner": "did:xcert:0xba0adddd91d8s8a8g73n2n5n12m5h1n5b3/200/latest"
}
- A cryptographic hash string.
- Created from digital asset data object.
- Supports any algorithm.
- Provable by creating the hash locally and then compare it with the one stored in token.
- Will support 0-proof-knowledge verification in the future.
- A JSON data object representing digital asset from the real-world.
- Includes ERC721Metadata JSON fields.
- Includes
cursor
for paginating asset revisions. - Includes
data
for disclosing asset data fields. - Served publically through HTTP where the URL should be formatted as
{protocol}://{domain}/dids/did:xcert:{contract-address}/{token-id}/{revision}
. - HTTP response includes a
Link
header pointing to JSON Schema definition where the URI should be formatted as{protocol}://{domain}/schemas/{asset-name}/{version}-metadata
.
Example:
GET https://0xcert.org/dids/did:xcert:0xff0asdjd38d8s8a8g73n2n5n12m3n1n5b2/100/latest HTTP/1.1
200 OK
Content-Type: application/json
Link: <https://0xcert.org/schemas/diploma/1.0.0-metadata> rel=describedBy
{
"description": "A document used to prove education of a person.",
"cursor": {
"current": "https://...",
"next": "https://...",
"prev": "https://..."
},
"data": {
"expires": "2020-01-01"
},
"image": "https://myimage.com/me.jpg",
"meta": {
"digestAlgorithm": "sha256",
"dateCreated": "2017-12-01",
"expires": "2020-01-01"
},
"name": "Diploma"
}