Privacy for private services

Controller and contact

Scope and access

This notice covers privately provided Matrix, authentication, web and real-time communication functions. They are not a public offer; accounts are created only following a personal invitation or approval. This page deliberately does not publish private service entry points.

Accounts, sign-in and devices

Account setup and operation may process:

• username, display name and internal user identifier,
• an email address where one is used,
• device identifiers, sessions, access and refresh tokens,
• login times, IP addresses and security events, and
• key material and public device keys for end-to-end encryption.

If optional Discord sign-in is chosen, Discord sends the identity details approved in that flow, particularly account ID, username/display name and possibly an email address. Discord is responsible for its own processing. For people in the European Economic Area, Discord identifies Discord Netherlands B.V. as the controller and states that data is also processed in the United States and other countries, relying in particular on adequacy decisions and standard contractual clauses. See the Discord privacy policy. Discord sign-in alone does not guarantee approval for a CaveTown account.

Messages, rooms and encryption

Matrix processes message events, room state, memberships, timestamps, reactions and technical delivery information. In end-to-end encrypted rooms, the server normally stores encrypted content, while metadata required for delivery and federation remains visible. Content in unencrypted rooms can be processed by servers.

CaveTown cannot reconstruct recovery keys or security phrases. Users must keep their own recovery information safe.

Media, calls and push notifications

Uploaded files, thumbnails and technical metadata are stored in the media store and delivered according to room permissions. Other homeservers may retrieve and retain copies for federated rooms under their own policies.

Voice, video and screen sharing process connection data, IP addresses, room association and transient media packets required for transmission. Transport or end-to-end encryption depends on the protocol, room and client used.

When a client enables push notifications, a push-gateway address, device identifier and limited notification data are sent to the push provider selected by the client. This can be an external operating-system or application provider. Depending on that provider, processing may occur outside the European Economic Area. The provider’s privacy information applies. Push can be disabled in the client.

Federation and external recipients

Communication with external Matrix users or participation in a federated room sends room events, identifiers, membership data, encrypted or unencrypted content and possibly media to participating homeservers. Those servers operate independently and retain data under their own policies. Local deletion therefore cannot reliably remove copies already federated elsewhere.

External homeservers can be located outside the European Economic Area. CaveTown cannot guarantee those independent operators’ legal bases, safeguards or deletion periods.

Logs and abuse prevention

Technical logs support troubleshooting, federation diagnosis and attack defence. They may contain IP address, time, requested endpoint, status, device or client information and internal error identifiers. Access data rotates by size; security-relevant events may be retained separately for an investigation or defensive action. The general privacy notice also describes the use of CrowdSec.

Hosting and technical providers

Services run on a netcup GmbH root server in Germany. Other recipients arise only when a selected feature requires them, such as Discord for optional sign-in, push providers, or external Matrix homeservers. Discord, push delivery and worldwide federation may involve third-country transfers; available safeguards depend on the recipient and the function selected by the user.

Purposes and legal bases

Processing provides invited communication, authentication, delivery, federation, backup, troubleshooting and system security. Where the GDPR applies, it is based in particular on Article 6(1)(b) where the service is provided at the user’s request and otherwise on Article 6(1)(f). Legitimate interests are stable private operation, protection of participants, and prevention of abuse and attacks.

Retention and deletion

• Account data is normally retained until account deletion or access ends.
• Room events and media remain where needed for room history, delivery and federation, or while deletion is not technically and legally possible.
• Transient real-time data is not retained as a call recording after the connection ends unless a separate recording function is expressly used.
• Access-protected backups are kept only as long as required for recovery and operational security. Deleted data may remain until the relevant backup is replaced.
• Legal retention, abuse prevention or legal claims may require longer storage in an individual case.

Rights, account deletion and complaints

Subject to the GDPR, data subjects may request access, correction, deletion, restriction, portability or object. Account-deletion and data requests can be sent to support@cavetown.de. Removal of copies held by independent federated operators cannot be guaranteed.

Data subjects may also complain to a supervisory authority. The relevant contact is stated in the general website privacy notice.