Identifying an untrusted issuing authority involves checking for several red flags:
Lack of Recognition: If the issuing authority is not recognized by major browsers or email clients, it is likely untrusted. Poor Reviews: Negative feedback and reviews from other users can be a clear indicator. No Accreditation: Accredited authorities often display certifications from organizations like WebTrust or CA/Browser Forum. Security Incidents: A history of security breaches or compromised certificates.