/**
 * @license
 * Copyright 2020 Google LLC
 * SPDX-License-Identifier: Apache-2.0
 */
import { Aead } from '../aead/internal/aead';
/**
 * A helper for DEM (data encapsulation mechanism) of ECIES-AEAD-HKDF.
 */
export interface EciesAeadHkdfDemHelper {
    /**
     * @return the size of the DEM key in bytes
     */
    getDemKeySizeInBytes(): number;
    /**
     * Creates a new `Aead` primitive that uses the key material given in
     * `demKey`, which must be of length `getDemKeySizeInBytes()`.
     *
     * @param demKey the DEM key.
     * @return the newly created `Aead` primitive.
     */
    getAead(demKey: Uint8Array): Promise<Aead>;
}