> ## Documentation Index
> Fetch the complete documentation index at: https://docs.dynamic.xyz/docs/llms.txt
> Use this file to discover all available pages before exploring further.

# ServerKeyShare

> Union type representing different types of server key shares for MPC operations

## Type Definition

```typescript theme={"system"}
type ServerKeyShare = 
  | EcdsaKeygenResult
  | Ed25519KeygenResult
  | BIP340KeygenResult;
```

## Description

`ServerKeyShare` is a union type that represents different types of key shares used in Multi-Party Computation (MPC) operations. The specific type depends on the signing algorithm used by the blockchain:

* **EVM chains**: Use `EcdsaKeygenResult` (ECDSA signing)
* **Solana**: Use `Ed25519KeygenResult` (Ed25519 signing)
* **Bitcoin**: Use `BIP340KeygenResult` (BIP340/Schnorr signing)

## Key Share Types

### EcdsaKeygenResult

Used for EVM chains (Ethereum, Polygon, etc.)

```typescript theme={"system"}
interface EcdsaKeygenResult {
  pubkey: EcdsaPublicKey;
  secretShare: string;
}
```

### Ed25519KeygenResult

Used for Solana and other Ed25519-based chains

```typescript theme={"system"}
interface Ed25519KeygenResult {
  pubkey: Uint8Array;
  secretShare: string;
}
```

### BIP340KeygenResult

Used for Bitcoin and BIP340/Schnorr-based chains

```typescript theme={"system"}
interface BIP340KeygenResult {
  pubkey: Uint8Array;
  secretShare: string;
}
```

## Example

```typescript theme={"system"}
import { ServerKeyShare } from '@dynamic-labs-wallet/node';

// EVM key share
const evmKeyShare: ServerKeyShare = {
  pubkey: {
    x: '0x1234567890abcdef...',
    y: '0xfedcba0987654321...'
  },
  secretShare: '0xabcdef1234567890...'
};

// Solana key share
const solanaKeyShare: ServerKeyShare = {
  pubkey: new Uint8Array([1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32]),
  secretShare: 'base64-encoded-secret-share'
};
```

## Usage

Server key shares are used in various MPC operations:

* **Wallet creation**: Generated during key generation ceremony
* **Message signing**: Used to create signatures
* **Transaction signing**: Used to sign transactions
* **Key backup**: Stored securely for wallet recovery

## Related Types

* [`Wallet`](/node/reference/types/wallet) - Wallet interface
* [`WalletProperties`](/node/reference/types/wallet-properties) - Wallet properties interface
* [`SigningAlgorithm`](/node/reference/types/signing-algorithm) - Signing algorithm enum