## 1) Certify digital documents
### a) **Presentation of the digitalDocument schema**
The **digitalDocument** schema is already anchored. Here is how it was built:
```json
{
"id": "c42e2516",
"name": "DigitalDocument",
"description": "An electronic file or document",
"version": "0.9.0",
"namespace": "archipels.io",
"hash_algorithm": "SHA256",
"matching_conditions": {
"or": [
"sha256"
]
},
"inputs": [
"sha256",
"dateCreated",
"expires",
"creator",
"category",
"description",
null,
null
],
"input_definitions": {
"sha256": {
"description": "The SHA-2 SHA256 hash of the content of the item.",
"standardization_function": "hexadecimal"
},
"dateCreated": {
"description": "The date on which the CreativeWork was created or the item was added to a DataFeed.",
"standardization_function": "formatDateTime"
},
"expires": {
"description": "Date the content expires and is no longer useful or available.",
"standardization_function": "formatDateTime"
},
"creator": {
"description": "The creator/author of this CreativeWork.",
"standardization_function": "replaceDiacritics.capitalize"
},
"category": {
"description": "A category for the item. Greater signs or slashes can be used to informally indicate a category hierarchy.",
"standardization_function": "digitalDocumentCategory"
},
"description": {
"description": "A description of the item.",
"standardization_function": ""
}
},
"metadatum_definitions": {
"sha256": {
"id": "i1",
"description": "The SHA-2 SHA256 hash of the content of the item.",
"mandatory": true,
"publication_flag": "searchable"
},
"dateCreated": {
"id": "i2",
"description": "The date on which the CreativeWork was created or the item was added to a DataFeed.",
"mandatory": true,
"publication_flag": "public"
},
"expires": {
"id": "i3",
"description": "Date the content expires and is no longer useful or available.",
"mandatory": true,
"publication_flag": "public"
},
"creator": {
"id": "i4",
"description": "The creator/author of this CreativeWork.",
"mandatory": true,
"publication_flag": "public"
},
"category": {
"id": "i5",
"description": "A category for the item. Greater signs or slashes can be used to informally indicate a category hierarchy.",
"mandatory": true,
"publication_flag": "public"
},
"description": {
"id": "i6",
"description": "A description of the item.",
"mandatory": true,
"publication_flag": "public"
}
}
}
```
See the next part *2. b. i. Create your proof schema* to know more about `*"*matching_conditions*"*`, `*"*standardization_function*"`,\* `*"*mandatory*"*` and `*"*publication_flag*"*`.
### **b) Create a digitalDocument proof**
Now you know how the schema is built, you can certify digital documents.\
First you must hash with SHA 256 your document using the following command to obtain the`"document_hash"` of your document.
```basic
$ openssl dgst -sha256 /document_path
```
There are the data you need to create a proof :
```c
"schema_id": "c42e2516",
"sha256": "<"0x"+"document_hash">",
"dateCreated" : "",
"expires": "",
"creator": "",
"category": "",
"description": "",
"secret" : "<12_characters_optional_secret>"
```
***WARNING*** : make sure to put “0x” before the `"document_hash"` of your document.
The secret is used to generate a nullifier. You can create a proof without filling in a secret, but one will be returned after each creation. Please keep these secrets as they are the only data allowing someone to nullify a proof.\
\
\&#xNAN;***WARNING*** : The `secret`must be a random number generated separately and kept safe as this is required to revoke the proof we've just created. A good secret should have a high entropy level. **For example : a good secret can be generated as an UUID, a hash or a password generated by a password manager.**\
\
**For the same proof, making requests one after the other without secret will trigger the creation of a proof twice and generate a new ID every calls.**\
\
Now you know how to structure a **digitalDocument** proof, you will find how to certify your proof in the 2. Certify your own proof part in the [Broken link](https://docs-v1.archipels.io/technical-documentation/integration-guide/certify/broken-reference "mention").
## 2) **Certify you type of proofs**
### **a) Create your own proof schema**
If you're creating a new type of proof, you have to create the schema first.
In the *production* environment, your proof schema will be created by the Archipels team after discussing of your use cases.
In the sandbox environment you’ll need the following information to create a proof schema.
The proof schema is the proof’s architecture. It is composed from :
* `"id"` : the proof schema identifier
* `"name"` : the name of the proof schema
* `"description"` : the description of the proof schema
* `"version"` : the version of the proof schema
* `"namespace"` : `“archipels.io”`
* `"hash_algorithm"` : `“SHA256”`
* `"inputs"` : the inputs you need to create and characterize a proof. For example : `“input_1”`. Note that the number of inputs must be equal to a power of 2. If you don’t have enough inputs you need to complete it with `null` rows to complete it up to the higher power of 2.
* `"input_definitions"` : for each input, you need to complete :
```json
"input_1" : {
"definition" : "",
"standardization_function": ""
}
```
* `"standardization_function"`:
* `capitalize`
* `digitalDocumentCategory`
* `formatDate`
* `formatDateTime`
* `hexadecimal`
* `removeSpaces`
* `replaceDiacritics`
* `"metadatum_definitions"` :
```json
"input_1": {
"id": "i1",
"description": "",
"mandatory": "",
"publication_flag": ""
}
```
See the ***References*** for more details about the `"id"`, the `"mandatory"` and the `"publication_flag"` inputs.
* `"id"`: identifier for the place of the Merkle tree where the input is. `"i"` identify the first stage, `"n"`is the second. When creating your schema, alway put `"i"`, Archipels can change it after exploring your use case.
* `"mandatory"`: `"true"` or `"false"`, it defines if the input is mandatory or not when creating a proof
* `"publication_flag"`:
* `"searchable"`: the input is a key for the proof verification, you can use it to identify the proof in the Archipels blockchain
* `"public"`: the input is disclosed when the proof verification is OK
* `"private"`: the input is not disclosed when the proof verification is OK
* `"matching_conditions"` : a boolean combination of inputs needed to make a proof verification OK
You can see an example of an existing proof schema in the part **1. Presentation of the digitalDocument schema** in [Broken link](https://docs-v1.archipels.io/technical-documentation/integration-guide/certify/broken-reference "mention") or in the example below with two inputs:
```json
{
"id": "0aaaaa3b",
"name": "Example",
"description": "Example of proof schema",
"version": "0.1.0",
"namespace": "archipels.io",
"hash_algorithm": "SHA256",
"inputs": [
"input_1",
"input_2",
"input_3",
null
],
"input_definitions": {
"input_1": {
"description": "Description of input_1",
"standardization_function": ""
},
"input_2": {
"description": "Description of input_2",
"standardization_function": "standardization_function"
},
"input_3": {
"description": "Description of input_3",
"standardization_function": ""
}
},
"metadatum_definitions": {
"input_1": {
"id": "i1",
"description": "Description of input_1",
"mandatory": true,
"publication_flag": "searchable"
},
"input_2": {
"id": "i2",
"description": "Description input_2",
"mandatory": true,
"publication_flag": "searchable"
},
"input_3": {
"id": "i3",
"description": "Description of input_3",
"mandatory": true,
"publication_flag": "public"
}
},
"matching_conditions": {
"and": [
"input_1","input_2"
]
}
}
```
Create a .json file (example.json for example) containing your proof schema.
There is the code to create the schema in the Trust Registry :
```json
POST /schemas -H 'Content-Type: application/json' --data '@example.json’
Host : ""
```
If the schema already exists you’ll get :
```json
{
"status": 409,
"message": "ProofSchemaExisting"
}
```
If it doesn’t, the Trust Registry will send you a ***201*** response with the details of your schema. The response for the example before is :
```json
{
"id": "0aaaaa3b",
"name": "Example",
"version": "0.1.0",
"hash_algorithm": "SHA256",
"tree_height": 2,
"description": "Example of proof schema",
"owner": null,
"namespace": "archipels.io",
"inputs": [
"input_1",
"input_2",
"input_3",
null
],
"input_definitions": {
"input_1": {
"description": "Description of input_1",
"standardization_function": ""
},
"input_2": {
"description": "Description of input_2",
"standardization_function": ""
},
"input_3": {
"description": "Description of input_3",
"standardization_function": ""
}
},
"metadatum_definitions": {
"input_1": {
"id": "i1",
"description": "Description of input_1",
"mandatory": true,
"publication_flag": "searchable"
},
"input_2": {
"id": "i2",
"description": "Description input_2",
"mandatory": true,
"publication_flag": "searchable"
},
"input_3": {
"id": "i3",
"description": "Description of input_3",
"mandatory": true,
"publication_flag": "public"
}
},
"matching_conditions": {
"and": [
"input_1",
"input_2"
]
}
}
```
Once you have created your proof schema, you can certify proofs using this schema on the Archipels Trust Registry.
### **b) Certify your own proof**
The data you need to create a proof are the `inputs` for which `mandatory`is `true`.
There is the an example based on the `"0aaaaa3b"`proof schema created in the part before.
```json
"schema_id": "0aaaaa3b",
"input_1": "",
"input_2": "",
"input_3": "",
"secret" : "<12_characters_optional_secret>"
```
The secret given is used to generate a nullifier. You can create a proof without giving a secret, but one will be returned after each creation. Please keep these secrets as they are the only data allowing someone to nullify a proof.
***WARNING*** : The `secret`must be a random number generated separately and kept safe as this is required to revoke the proof we've just created. A good secret should have a high entropy level. **For example : a good secret can be generated as an UUID, a hash or a password generated by a password manager.**
**For the same proof, making requests one after the other without secret will trigger the creation of a proof twice and generate a new ID every calls.**
If one of your inputs is a document hash, you can use the command below to compute the `sha256` of your document :
```json
$ openssl dgst -sha256 //.
```
Then, the input would be
```json
"document_hash": "<"Ox"+"sha256">"
```
***WARNING*** : make sure to put “0x” before the `"sha256"` of your document.
The command you need to create a proof in the Trust Registry are :
* if you want to create it from data :
```c
POST /proofs -H 'Content-Type: application/json' --data '{ "schema_id": "0aaaaa3b", "secret" : "<12_characters_optional_secret>", "data": { "input_1": "","input_2": "", "input_3": "" }}'
Host : ""
```
* if you want to create it from a .json file (example.json for example) :
Here is the example.json file :
```json
{
"schema_id": "0aaaaa3b",
"data": {
"input_1": "",
"input_2": "",
"input_3": "",
},
"secret": "<12_characters_optional_secret>"
}
```
And the command :
```json
POST /proofs -H 'Content-Type: application/json' --data '@example.json'
Host : ""
```
* If you want to create a proof directly from a datahash that you computed from a JSON containing all inputs :
```basic
POST /proofs/verify -H 'Content-Type: application/json' --data '{ "schema_id": "0aaaaa3b", "data_hash": ""}'
Host : ""
```
***WARNING*** : If `.env` file doesn't contain an `ISSUER_ID`, or a `PRIVATE_KEY`you will get a message like this `A properly set up identity is required in order to create a proof.`
If it doesn’t, the Trust Registry will send you a ***202*** or response with the details of your proof.
For example, if you want to create a proof with the following .json from the **digitalDocument** schema of `"schema_id" : "c42e2516"` , here are the inputs :
```json
{
"schema_id": "c42e2516",
"data": {
"sha256": "0x298d499999f5018b267b703990d8974e54505c69aa16e697a2026205abf3fc85",
"dateCreated" : "December 24, 2022 23:59:59",
"expires": "December 24, 2023 23:59:59",
"creator": "Archipels",
"category": "PAYSLIP",
"description": "example"
},
"secret": "secret_secret_secret"
}
```
The Trust Registry will return a *code 202* response :
```json
{
"proof": {
"id": "f9312476003c3bd51a2faefe128ef9affa64ed1e6acd3e35f1d5529651af1e05",
"commitment": "4eec9aa957ccb0ad3245e04fc61692de43a9d1c02f7b1dabdd7e46466cdae046",
"commitment_details": {
"schema_id": "c42e2516",
"data_hash": "f4303f4da60deebbca059dbda307159c8c6d5d798d8196a2e0a406f09eab2d19",
"nullifier": "ea3fa1672a240f69a0a0240be9c161f8631d2c5b2a2f9829d68329047bff7051",
"issuer_id": "17e28cbbde064617391bdac3282c2c50b33f9baba8bb509d60aca557500ab90c",
"signature": "7e8d405c446a1f982a5b6ebd2f130cc9b35e2675ec79815a69c13c02e327d0132824abc1c944eb4534fa96b0a6653bd1d1ef9a701c49b70ade2004127c458e0e"
},
"anchor_id": "0000000000000000000000000000000000000000000000000000000000000001",
"metadata": {
"sha256": {
"value": "298d499999f5018b267b703990d8974e54505c69aa16e697a2026205abf3fc85",
"inclusion_proof": [
"51a4fa9b4a39792017db0fe1fa75316741815498106bc515025a78c528a81601",
"5361724dc6cf58aceba888cd873949d323d30eb7e6a109ddc5b1449c55f4c64e",
"5850c9cc205646efcc54cc61fa278672f1febac2854e4b1b2cb91acbca7847a3"
],
"publication_flag": "searchable"
},
"dateCreated": {
"value": "2022-12-24T23:59:59",
"inclusion_proof": [
"e0f149baa1db0413137dd49ed2ebb4e99086e74fac4d477aedd797f0e594addf",
"5361724dc6cf58aceba888cd873949d323d30eb7e6a109ddc5b1449c55f4c64e",
"5850c9cc205646efcc54cc61fa278672f1febac2854e4b1b2cb91acbca7847a3"
],
"publication_flag": "public"
},
"expires": {
"value": "2023-12-24T23:59:59",
"inclusion_proof": [
"e15fc0f1e72b93eb4134fafa5a6f81f33c09fc7d95930c51e2cb5cb55f8226df",
"b2c111f81a0386a62f69cdcee52f782b0720a5a6729148574c3af972ba361111",
"5850c9cc205646efcc54cc61fa278672f1febac2854e4b1b2cb91acbca7847a3"
],
"publication_flag": "public"
},
"creator": {
"value": "ARCHIPELS",
"inclusion_proof": [
"b20d7deaebe7baf78f625ed7b459c99e7ac4721150a97aca327f3ab4af71894d",
"b2c111f81a0386a62f69cdcee52f782b0720a5a6729148574c3af972ba361111",
"5850c9cc205646efcc54cc61fa278672f1febac2854e4b1b2cb91acbca7847a3"
],
"publication_flag": "public"
},
"category": {
"value": "PAYSLIP",
"inclusion_proof": [
"50d858e0985ecc7f60418aaf0cc5ab587f42c2570a884095a9e8ccacd0f6545c",
"2dba5dbc339e7316aea2683faf839c1b7b1ee2313db792112588118df066aa35",
"f335f8ee2d316e458fc56228318b1d0034580cca9c5447dc3e8f49ce4ec9b1f5"
],
"publication_flag": "public"
},
"description": {
"value": "example",
"inclusion_proof": [
"76d74e17240f1c3a5e2dbc56210dbfd5ccb4374be9cafd61cd14aedc9e4a2670",
"2dba5dbc339e7316aea2683faf839c1b7b1ee2313db792112588118df066aa35",
"f335f8ee2d316e458fc56228318b1d0034580cca9c5447dc3e8f49ce4ec9b1f5"
],
"publication_flag": "public"
}
},
"accumulator_id": 63793,
"status": "pending"
},
"secret": "secret_secret_secret",
"qrCodeBase64": "data:image/gif;base64,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"
}
```
The `"status"`can be :
* `"pending"`: Proof saved in the database but is waiting to be registered in our accumulator
* `"registered"`: Proof saved in our accumulator
* `"included"`: Proof anchored in the blockchain
The `"nullifier"` is required along with the `"secret"` if you choose to revoke a proof.
The `"qrCodeBase64"`is the url where you can find the QRcode of the proof.
After creating a proof you should verify it. So let’s check the [verify](https://docs-v1.archipels.io/technical-documentation/integration-guide/verify "mention") part.
You can aslo revoke it if needed. For that, you can read the next part [Broken link](https://docs-v1.archipels.io/technical-documentation/integration-guide/certify/broken-reference "mention")
## 3) Revoke proofs
Once revoked, the proof will then be marked as revoked in any future verification.\
There is the command you need to do it :
```json
POST /proofs/revoke -H 'Content-Type: application/json' --data '{ "nullifier": "", "secret": "<12_characters_optional_secret>", "message": ""}'
Host : ""
```
Note that the `"message"` is optional, if it’s missing it will automatically be set as `"Proof revoked"`. If it worked, the response will be a code 200 response.
Here is an example of proof revocation and the Trust Registry response:
```json
POST /proofs/revoke -H 'Content-Type: application/json' --data '{"nullifier": "ea3fa1672a240f69a0a0240be9c161f8631d2c5b2a2f9829d68329047bff7051", "secret": "secret_secret_secret" }'
Host : ""
```
Response : *Code 200*
```json
{
"nullifier": "ea3fa1672a240f69a0a0240be9c161f8631d2c5b2a2f9829d68329047bff7051",
"secret": "secret_secret_secret",
"message": "Proof revoked"
}
```