export declare class X25519KeyPair {
    private privateKey;
    publicKey: Uint8Array;
    constructor(privateKey?: Uint8Array);
    getPrivateKey(): Uint8Array;
    getPublicKey(): Uint8Array;
    getPrivateKeyHex(): string;
    getPublicKeyHex(): string;
    static fromPrivateKeyHex(hexPrivateKey: string): X25519KeyPair;
}