Authentication SMS for Advanced E-Signatures (AES)

We are currently experiencing a degradation in the delivery of authentication SMS for advanced e-signatures (AES).Our team is investigating the issue and working with our provider to restore full functionality.We will provide an update as soon as we have more information.

We have identified the source of the issue and **closed the entry point**. To **re-enable AES signing for non-Swiss phone numbers**, we need to **deploy an update**, which is scheduled for **tomorrow morning**.No customer data was at risk: the exploit misused our messaging system to trigger SMS messages, which led to an **automated shutdown** due to unusually high volume.More updates will follow as soon as the deployment is completed.

We have identified the issue; it only affects authentication SMS sent to **non-Swiss phone numbers**.Our team is working with our SMS provider to resolve the problem and restore full delivery.We will provide an update as soon as we have more information.

The issue has been **resolved**.**AES signing for non-Swiss phone numbers is fully operational again.**More details will follow in a post-incident report.

The issue has **reopened**.A **backlog of undelivered messages** is currently affecting the delivery of new authentication SMS.We are working on a solution and will provide an update as soon as more information is available.

The issue has been **resolved**.All authentication SMS are now **fully operational again**.

Due to **fraudulent use of our SMS authentication service**, all authentication SMS to **non-Swiss phone numbers** are currently **blocked** for signing with AES. We are actively investigating the source of the abuse and working to **close the exploited gap**.In the meantime, we recommend using **SES** or **QES** signature levels as alternatives.We will provide an update as soon as we have more information.

**Incident Summary (31.10.2025 – 03.11.2025)** We experienced abuse of SMS resends in **trial accounts**, where SMS messages were sent to **high-cost numbers outside the EU and CH**. After detection, the **SMS gateway was temporarily deactivated** while we analyzed the issue and implemented countermeasures. **Impact:*** Financial loss to Skribble only* No customer data affected or exposed**Countermeasures:*** Trial (non-paying) accounts can no longer send SMS outside defined “safe” countries* Paying customers remain unrestrictedWe apologize for the disruption during this period. The temporary outage was necessary to ensure no security breach and to protect our customers from any negative impact. Sincerely, Waldemar Dick (CTO)

We have detected new issues with sending authentication SMS to **certain EU countries**.Currently, AES signatures for signers with **German** and **French** phone numbers are **not functioning**. At this stage, we cannot rule out that **additional countries** may also be affected.We are investigating the full scope of the problem and are in contact with our SMS provider to resolve it.More updates will follow as soon as we have additional information.

We can now confirm that the issue affects **all non-Swiss phone numbers**, not only German and French numbers as initially observed. Authentication SMS for AES currently work **only** with Swiss numbers.We are in direct contact with our SMS provider to resolve the issue as quickly as possible.We will provide another update as soon as we have more information.