Session creation

High level flow of DuoSession

• Configure/Implement transport layer (WebSocketClient)
• Configure/Implement storage layer (StorageClient)
• Create DuoSession
• Perform MPC actions

DuoSession is the main object which will be used to perform all of the MPC operations supported. To create DuoSession please follow the steps below.

Step 1 : Add library to your Project

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• Create new xcode project if you haven't.

• Add SilentShard-Duo SDK using the instructions from the Installation Guide

Step 2 : Create new session

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• Import module - silentshardduo.
• We can Create DuoSession by calling SilentShard.ECDSA.createDuoSession() or SilentShard.EdDSA.createDuoSession() (whichever applies) by providing the following parameters
• Provide websocket client by using any of the below options :
  1. Providing WebsocketConfig object to let SDK use default WebsocketClient i.e. SilentShardWebsocketClient.
  2. Providing custom WebsocketClient overriding(extending) SilentShardWebsocketClient to override existing connect, read or write, etc. methods to add your own logic/configuration or additional process.
  3. Providing custom WebsocketClient (Your Custom WebsocketClient Implementation) by extending WebsocketClient
• Provide cloud/server public key.
• Provide storage client. (You need to implement the interface StorageClient).

Example

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ECDSA

Example.swift

import silentshardduo

let CLOUD_NODE_URI = "192.168.1.4"
let PORT = "8080"

//Other party verifying-key/public-key
let cloudPublicKey = "---------Hex---------"

//Create websocketConfig to let SilentShard use default WebsocketClient.
let websocketConfig: silentshardduo.WebsocketConfig =
        WebsocketConfigBuilder()
        .withBaseUrl(CLOUD_NODE_URI)
        .withPort(PORT)
        .withSecure(false)
        //If applies
        .withAuthenticationToken("")
        .build()
        
//Create storage client instance to manage keyshare state
let storageClient = CustomStorageClient()

//Create duoSession

/*Option: 1 : Using Default WebsocketClient.
We only have to pass websocketConfig which contains the server config and 
communication will be handled by internal websocketClient*/
let duoSession = SilentShard.ECDSA.createDuoSession(
                    cloudVerifyingKey: String(cloudVerifyingKey),
                    websocketConfig: websocketConfig,
                    storageClient: storageClient)

/*Option: 2 : Using Customised SilentShardWebsocketClient.
ExtendedSilentShardWebsocketClient(example name and You implement) extends SilentShardWebsocketClient(Internally extends WebsocketClient)
from SilentShard. You can 
override connect, read, write, etc. according to your configuration.*/
let duoSession = SilentShard.ECDSA.createDuoSession(
            cloudVerifyingKey: String(cloudVerifyingKey),
            // `ExtendedSilentShardWebsocketClient` is a example name
            websocketClient: ExtendedSilentShardWebsocketClient(),
            storageClient: storageClient)

/*Option: 3 : Using Custom (Your Implementation) WebsocketClient.
CustomWebsocketClient(example name) extends WebsocketClient from SilentShard.
It will have your own httpClient and other customization. In other words, If you wish to write 
your own websocket client from scratch.*/
let duoSession = SilentShard.ECDSA.createDuoSession(
            cloudVerifyingKey: String(cloudVerifyingKey),
            // `CustomWebsocketClient` is a example name
            websocketClient: CustomWebsocketClient(),
            storageClient: storageClient)

EdDSA

Example.swift

import silentshardduo

let CLOUD_NODE_URI = "192.168.1.4"
let PORT = "8080"

//Other party verifying-key/public-key
let cloudPublicKey = "---------Hex---------"

//Create websocketConfig to let SilentShard use default WebsocketClient.
let websocketConfig: silentshardduo.WebsocketConfig =
        WebsocketConfigBuilder()
        .withBaseUrl(CLOUD_NODE_URI)
        .withPort(PORT)
        .withSecure(false)
        //If applies
        .withAuthenticationToken("")
        .build()
        
//Create storage client instance to manage keyshare state
let storageClient = CustomStorageClient()

//Create duoSession

/*Option: 1 : Using Default WebsocketClient.
We only have to pass websocketConfig which contains the server config and 
communication will be handled by internal websocketClient*/
let duoSession = SilentShard.EdDSA.createDuoSession(
                    cloudVerifyingKey: String(cloudVerifyingKey),
                    websocketConfig: websocketConfig,
                    storageClient: storageClient)

/*Option: 2 : Using Customised SilentShardWebsocketClient.
ExtendedSilentShardWebsocketClient(example name and You implement) extends SilentShardWebsocketClient(Internally extends WebsocketClient)
from SilentShard. You can 
override connect, read, write, etc. according to your configuration.*/
let duoSession = SilentShard.EdDSA.createDuoSession(
            cloudVerifyingKey: String(cloudVerifyingKey),
            // `ExtendedSilentShardWebsocketClient` is a example name
            websocketClient: ExtendedSilentShardWebsocketClient(),
            storageClient: storageClient)

/*Option: 3 : Using Custom (Your Implementation) WebsocketClient.
CustomWebsocketClient(example name) extends WebsocketClient from SilentShard.
It will have your own httpClient and other customization. In other words, If you wish to write 
your own websocket client from scratch.*/
let duoSession = SilentShard.EdDSA.createDuoSession(
            cloudVerifyingKey: String(cloudVerifyingKey),
            // `CustomWebsocketClient` is a example name
            websocketClient: CustomWebsocketClient(),
            storageClient: storageClient)

• CLOUD_NODE_URI is the URI of the cloud node.
• cloudPublicKey is the cloud verifying key (Ed25519 public key).
  • This public key is used to verify the server's signature on each message
  • See example here
• SilentShard Provides API for creating MPC DuoSession (Two-Party) using ECDSA algorithm.
• ECDSA Provides factory methods for creating MPC session using ECDSA algorithm.
• DuoSession Represents a two-party computation session that lets you perform MPC operations using SilentShard protocol.

You have now successfully set up the session and are ready to start performing MPC actions! 🎉