import { ConfigService } from '@nestjs/config';
export declare class HashChainService {
    private readonly configService;
    private readonly logger;
    private readonly hmacSecret;
    constructor(configService: ConfigService);
    generateHash(data: any): Promise<string>;
    private sortObject;
    generateSignature(data: any): Promise<string>;
    verifySignature(data: any, expectedSignature: string): Promise<boolean>;
    verifyHashChain(logs: any[]): Promise<{
        success: boolean;
        failures: Array<{
            index: number;
            logId: string;
            type: 'HASH_CHAIN_BROKEN' | 'HASH_MISMATCH' | 'INVALID_GENESIS' | 'SIGNATURE_INVALID';
            message: string;
            expectedHash?: string;
            actualHash?: string;
        }>;
    }>;
}