import java.util.concurrent.Executor;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Future;
import java.util.concurrent.RejectedExecutionException;
import java.util.concurrent.ScheduledExecutorService;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.TimeoutException;
import java.util.concurrent.atomic.AtomicBoolean;
import java.util.logging.LogRecord;
import java.util.logging.Logger;

    private final Map<String, Long> keyCreationTimes = new ConcurrentHashMap<>();
    private final Map<String, Integer> keyVersions = new ConcurrentHashMap<>();
    private final java.util.concurrent.ScheduledExecutorService rotationScheduler =
            java.util.concurrent.Executors.newSingleThreadScheduledExecutor(r -> {
                Thread t = new Thread(r, "SecureKeyManager-Rotation");
                t.setDaemon(true);