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Classes

Class: CurvePoint

export class CurvePoint {
    constructor(wallet: Wallet) 
    async encrypt(message: number[], protocolID: WalletProtocol, keyID: string, recipients: string[], administrators?: string[]): Promise<{
        encryptedMessage: number[];
        header: number[];
    }> 
    async decrypt(ciphertext: number[], protocolID: WalletProtocol, keyID: string): Promise<number[]> 
    buildHeader(senderPublicKey: string, recipients: string[], encryptedKeys: {
        ciphertext: number[];
    }[], administrators: string[], currentVersion: number): number[] 
    parseHeader(ciphertext: number[]): {
        header: number[];
        message: number[];
        administrators: string[];
    } 
    async addParticipant(iheader: number[], protocolID: WalletProtocol, keyID: string, newParticipant: string): Promise<number[]> 
    async removeParticipant(iheader: number[], targetParticipant: string): Promise<number[]> 
}

Constructor

Initializes a new CurvePoint instance.

constructor(wallet: Wallet) 

Argument Details

• wallet
  • The wallet instance providing cryptographic operations.

Method addParticipant

Adds a new participant to an existing message group.

async addParticipant(iheader: number[], protocolID: WalletProtocol, keyID: string, newParticipant: string): Promise<number[]> 

Returns

The updated message header as an array of bytes.

Argument Details

• iheader
  • The original message header as an array of bytes.
• protocolID
  • The protocol ID defining cryptographic context.
• keyID
  • A unique identifier for the key used.
• newParticipant
  • The public key of the new participant in hex format.

Method buildHeader

Builds a message header containing recipient and administrator information.

buildHeader(senderPublicKey: string, recipients: string[], encryptedKeys: {
    ciphertext: number[];
}[], administrators: string[], currentVersion: number): number[] 

Returns

The constructed header as an array of bytes.

Argument Details

• senderPublicKey
  • The sender's public key in hex format.
• recipients
  • An array of recipient public keys in hex format.
• encryptedKeys
  • An array of objects containing encrypted symmetric keys.
• administrators
  • An array of administrator public keys in hex format.
• currentVersion
  • The current header version number.

Method decrypt

Decrypts a message intended for the recipient.

async decrypt(ciphertext: number[], protocolID: WalletProtocol, keyID: string): Promise<number[]> 

Returns

The decrypted message as an array of bytes.

Argument Details

• ciphertext
  • The ciphertext containing the message header and encrypted message.
• protocolID
  • The protocol ID defining cryptographic context.
• keyID
  • A unique identifier for the key used.

Method encrypt

Encrypts a message for a group of recipients.

async encrypt(message: number[], protocolID: WalletProtocol, keyID: string, recipients: string[], administrators?: string[]): Promise<{
    encryptedMessage: number[];
    header: number[];
}> 

Returns

An object containing the encrypted message and the message header.

Argument Details

• message
  • The plaintext message to encrypt as an array of bytes.
• protocolID
  • The protocol ID defining cryptographic context.
• keyID
  • A unique identifier for the key used.
• recipients
  • An array of recipient public keys in hex format.
• administrators
  • (Optional) An array of administrator public keys.

Method parseHeader

Parses a message header and extracts key information.

parseHeader(ciphertext: number[]): {
    header: number[];
    message: number[];
    administrators: string[];
} 

Returns

An object containing the parsed header, message, and administrator list.

Argument Details

• ciphertext
  • The ciphertext containing the header and message.

Method removeParticipant

Removes a participant from the message group. Only administrators are authorized to perform this action.

async removeParticipant(iheader: number[], targetParticipant: string): Promise<number[]> 

Returns

The updated message header as an array of bytes.

Argument Details

• iheader
  • The original message header as an array of bytes.
• targetParticipant
  • The public key of the participant to remove in hex format.

Usage Examples

Encrypt and Decrypt a Message

import { CurvePoint } from 'curvepoint';
import { Wallet } from '@bsv/sdk';

// Step 1: Initialize a wallet instance
const wallet = new Wallet(/* ... wallet configuration ... */);

// Step 2: Create a CurvePoint instance
const curvePoint = new CurvePoint(wallet);

// Step 3: Encrypt a message
const message = [1, 2, 3, 4, 5];
const recipients = ['recipientPublicKey1', 'recipientPublicKey2'];
const administrators = ['adminPublicKey1', 'adminPublicKey2'];
const protocolID = ['App', 'exampleProtocol'];
const keyID = 'exampleKey';

const { encryptedMessage, header } = await curvePoint.encrypt(
    message,
    protocolID,
    keyID,
    recipients,
    administrators
);

// Step 4: Decrypt the message as a recipient
const decryptedMessage = await curvePoint.decrypt(
    [...header, ...encryptedMessage],
    protocolID,
    keyID
);

console.log('Decrypted Message:', decryptedMessage);

Add a Participant to an Existing Header

const updatedHeader = await curvePoint.addParticipant(
    header,
    protocolID,
    keyID,
    'newParticipantPublicKey'
);

console.log('Updated Header:', updatedHeader);

Remove a Participant (Administrator Only)

try {
    const updatedHeader = await curvePoint.removeParticipant(
        header,
        'participantToRemovePublicKey'
    );

    console.log('Header after participant removal:', updatedHeader);
} catch (error) {
    console.error('Failed to remove participant:', error.message);
}

Links: API, Classes