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trustd (Trust Evaluation Daemon) is a safe macOS security process. trustd is the macOS daemon responsible for evaluating certificate trust chains. Whenever your Mac needs to verify an SSL/TLS certificate for a website, validate a code signature, or check a developer identity, trustd performs the cryptographic validation against the system's certificate trust store and any user-installed certificates. trustd making occasional network requests and using brief CPU spikes during certificate validation is completely normal. Be concerned if trustd is making constant rapid network connections to unknown hosts — this could indicate a compromised certificate store or man-in-the-middle attack attempting to inject rogue certificates.

Security Process

What is trustd on Mac?

Trust Evaluation Daemon

Safe

trustd is the macOS daemon responsible for evaluating certificate trust chains. Whenever your Mac needs to verify an SSL/TLS certificate for a website, validate a code signature, or check a developer identity, trustd performs the cryptographic validation against the system's certificate trust store and any user-installed certificates.

Common Issues

High CPU or network usage when validating certificates for many simultaneous connections

SSL errors in Safari or other apps when trustd cannot reach OCSP responders

Slow application launches due to code signature verification delays

Certificate trust failures after system clock changes or expired root certificates

How to Fix

1

Check your system date and time

Go to System Settings > General > Date & Time and ensure 'Set date and time automatically' is enabled. Incorrect system time causes certificate validation failures because certificates have validity periods that depend on accurate timestamps.

2

Clear the OCSP and CRL cache

Open Keychain Access, go to Keychain Access > Settings, and click 'Reset My Default Keychains.' Alternatively, delete cached OCSP responses from ~/Library/Keychains/ to force trustd to refetch fresh certificate status data.

3

Check network connectivity to Apple's OCSP servers

trustd contacts ocsp.apple.com and other OCSP responders to check certificate revocation status. If your network blocks these connections (corporate firewall, VPN, or DNS filter), trustd will time out and cause delays. Ensure ocsp.apple.com is accessible.

4

Update macOS to refresh root certificates

Apple periodically updates the trusted root certificate store through macOS updates. If you're seeing trust failures with well-known sites, check System Settings > General > Software Update for pending updates that may include certificate store refreshes.

When to Worry

trustd making occasional network requests and using brief CPU spikes during certificate validation is completely normal. Be concerned if trustd is making constant rapid network connections to unknown hosts — this could indicate a compromised certificate store or man-in-the-middle attack attempting to inject rogue certificates.

How CoreLock Helps

CoreLock verifies the code signing certificates of all running applications and installed software, detects unsigned or improperly signed binaries, and alerts you to expired or revoked developer certificates that trustd would flag during normal operation.

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Frequently Asked Questions

What does trustd do on Mac?

trustd evaluates whether digital certificates are trustworthy. Every time you visit an HTTPS website, open a signed application, or install software, trustd checks the certificate chain to verify identity and integrity. It contacts OCSP (Online Certificate Status Protocol) servers to check whether certificates have been revoked.

Why is trustd using my network?

trustd connects to OCSP responders (like ocsp.apple.com) to verify that certificates haven't been revoked. This happens when you visit websites, launch signed apps, or install updates. The network usage is normal security behavior — it's your Mac checking that the things it's connecting to are legitimately who they claim to be.

Is trustd safe?

Yes. trustd is a core Apple security daemon that protects you from fraudulent certificates and compromised connections. It is code-signed by Apple, runs as a system service managed by launchd, and is protected by System Integrity Protection. It plays a critical role in macOS's security architecture.

Monitor Mac Processes with CoreLock

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