export declare function encrypt(data: unknown, key: Uint8Array): Promise<{
    n: string;
    c: string;
    z?: boolean;
}>;
export declare function decrypt(encrypted: {
    n: string;
    c: string;
    z?: boolean;
}, key: Uint8Array): Promise<unknown | null>;
export declare function isEncrypted(msg: unknown): msg is {
    n: string;
    c: string;
    z?: boolean;
};
export declare function decodeKey(encodedKey: string): Uint8Array;
export declare function parseMessage(data: string, sessionKey: Uint8Array | null): Promise<Record<string, unknown> | null>;
export declare function encryptAndSend(ws: {
    send: (data: string) => void;
    readyState: number;
}, msg: unknown, sessionKey: Uint8Array | null): Promise<void>;
export declare function encryptAndSendConfirmed(ws: {
    send: (data: string, callback: (error?: Error) => void) => void;
    readyState: number;
}, msg: unknown, sessionKey: Uint8Array | null): Promise<void>;
export interface E2EEnvelope {
    e2e: true;
    n: string;
    c: string;
    z?: boolean;
}
/**
 * E2E-encrypt data with the shared e2eKey.
 * Wraps the existing encrypt() output with an `e2e: true` flag.
 */
export declare function e2eEncrypt(data: unknown, e2eKey: Uint8Array): Promise<E2EEnvelope>;
/**
 * E2E-decrypt an E2E envelope. Returns null on failure.
 */
export declare function e2eDecrypt(msg: {
    n: string;
    c: string;
    z?: boolean;
}, e2eKey: Uint8Array): Promise<unknown | null>;
/**
 * Check if a message is an E2E-encrypted envelope (has e2e: true + n + c).
 */
export declare function isE2EEncrypted(msg: unknown): msg is E2EEnvelope;