import type { RecipientPublicKey } from './epochCrypto.js';
/**
 * Whether a string is an Ed25519 `did:key` DID -- the only controller shape a
 * recipient key can be derived from (an X25519 twin exists only for an Ed25519
 * key). A key id (a DID with a fragment) is not one: the derivation is defined
 * over the DID itself.
 *
 * @param did {string | undefined}
 * @returns {boolean}
 */
export declare function isEd25519DidKey(did: string | undefined): boolean;
/**
 * Derives the X25519 epoch-recipient public key for an Ed25519 `did:key`
 * controller.
 *
 * @param options {object}
 * @param options.did {string}   the grantee's Ed25519 `did:key` DID
 * @returns {RecipientPublicKey}
 */
export declare function x25519RecipientFromDidKey({ did }: {
    did: string;
}): RecipientPublicKey;
//# sourceMappingURL=didKeyRecipient.d.ts.map