SelloPrivacy policy
Updated 6 September 2026
Who is responsible
NEGATIVE EPSILON, S.L., Spain, is responsible for personal data processed through this website and Sello support. Contact us at contact@negativeepsilon.com. This policy covers the Sello app, this website and support enquiries.
Your documents and certificates
Sello processes PDFs on your Mac. It does not upload them to our servers. Private-key operations use macOS Keychain; Sello does not export those keys. Temporary files are removed when an operation finishes normally. An unexpected termination may leave temporary files inside the app’s local container.
Accounts, purchases and diagnostics
Sello requires no account of its own and includes no analytics or advertising. Apple handles purchases and may process purchase or diagnostic data according to your settings and its privacy policy.
This website
This site uses no analytics cookies, advertising or third-party fonts. To deliver pages, the server receives technical information such as your IP address and the requested URL.
If you contact us
We receive your email address and the contents of your message to respond and resolve your query. Avoid sending confidential information or private keys. You can request deletion of your conversation by writing to the same contact.
Contact
For privacy questions, email contact@negativeepsilon.com.
Purposes and legal bases
We use support messages to answer questions and provide assistance with your purchase (performance of a contract or steps you request before a purchase). We process technical request data to deliver and protect the website (our legitimate interest in operating a reliable, secure service). We may retain records where required by law. We do not sell personal data or use it for advertising or automated decisions.
Retention and service providers
Support correspondence is kept for as long as needed to resolve your enquiry and handle related follow-up or claims. Technical records are kept only as needed for security and troubleshooting; records relevant to an incident may be retained until it is resolved. Hosting and email providers may process these data to provide their services. We do not receive your payment card details from Apple.
Your rights
You can contact us to request access, correction, erasure, restriction or portability of your data, or object to processing based on legitimate interests, where applicable. You may also complain to the Spanish Data Protection Agency (AEPD) or your local data protection authority. Providing support information is voluntary; without it we may be unable to resolve your query.