SwissSign: duplicate serial number

RESOLVED FIXED SwissSign AG

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AI Summary

SwissSign AG reported a case of duplicate serial numbers in certificates issued by their CA, specifically for the 'SwissSign EV Gold CA 2014 - G22'. Two certificates were identified with the same serial number but differing in the Certificate Policies extension. The issue was discovered by Andrew Ayer on November 17, 2020, prompting SwissSign to analyze and confirm the problem. They implemented a technical safeguard and revoked the affected certificate by November 20, 2020. The CA has since made changes to their processes to prevent future occurrences and confirmed that the necessary updates were deployed by late April 2021.

Model: gpt-4o-mini Generated: 2026-06-13 20:50 UTC Revised: 2026-06-16 18:18 UTC Confidence: 0.85 15 comments

Chronology

2020-11-17 Duplicate serial number issue discovered and reported.
2020-11-20 Affected certificate revoked.
2021-04-30 System updates deployed to prevent future issues.

Thread Activity

2020-11-17 Mm representative — Reported duplicate serial number issue with SwissSign certificates.
2020-11-18 SwissSign AG — Confirmed receipt of the report and outlined a timeline for response.
2020-11-23 SwissSign AG — Confirmed revocation of the affected certificate.
2021-04-30 SwissSign AG — Confirmed deployment of updates to prevent similar issues.

Participants

Mm representative SwissSign AG Community commenter Mozilla representative

External References

Original Bugzilla Case

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