public java.util.Map<String, Long> getKeyRotationMetrics() {
        java.util.Map<String, Long> metrics = new java.util.HashMap<>();
        metrics.put("totalRotations", totalKeyRotations.get());
        metrics.put("lastRotationTime", lastKeyRotationTime.get());
        metrics.put("bytesEncryptedSinceLastRotation", bytesEncrypted.get());
        metrics.put("timeSinceLastRotation", System.currentTimeMillis() - encryptionStartTime);