/**
 * Encrypted equality indexes — spec § EDV Usage § Indexes.
 *
 * Client-side HMAC-SHA-256 over attribute name + value. The server
 * never sees plaintext; it matches HMAC bytes verbatim during query.
 */
export interface IndexedAttribute {
    name: string;
    value: string;
    unique?: boolean;
}
export interface IndexEntry {
    hmac: {
        id: string;
        type: 'Sha256HmacKey2019';
    };
    sequence: number;
    attributes: IndexedAttribute[];
}
export declare class IndexComputer {
    private readonly key;
    readonly keyId: string;
    constructor(opts: {
        key: Uint8Array;
        keyId: string;
    });
    hmac(plaintext: string): string;
    buildEntry(args: {
        sequence: number;
        attributes: Record<string, string>;
        uniqueKeys?: string[];
    }): IndexEntry;
}
/**
 * Server-side query predicate. Returns true iff some indexed block
 * contains an attribute matching the HMAC name + value pair.
 */
export declare function matchesQuery(indexed: Array<Record<string, unknown>>, hmacName: string, hmacValue: string): boolean;