AlgeviaLegal
Privacy policy
Last updated: 18 September 2026
1. Controller
Finn Silas Adams
Adolf-Pohlmann-Straße 10
24376 Kappeln, Germany
E-mail: business.algevia@gmail.com
2. What this website is
Algevia sells collections of mathematics problems as PDF files. This policy describes which data is processed in the course of that, for what purpose, and what rights you have.
The website uses no analytics, advertising or tracking services. There are no third-party embeds, no social media plug-ins and no newsletters. Fonts are served from our own server.
3. Hosting
The website is hosted by Vercel Inc., 440 N Barranca Ave #4133, Covina, CA 91723, USA. Server functions run in the Frankfurt am Main data centre; static content is delivered through Vercel's worldwide network.
When you access the website, Vercel processes technically necessary access data: IP address, date and time, requested address, amount of data transferred, browser and operating system identifiers. This data serves delivery, security and error analysis. The legal basis is Art. 6 (1) (f) GDPR (legitimate interest in secure operation). A data processing agreement is in place with Vercel. Insofar as data is transferred to the USA, this is done on the basis of the EU Commission's standard contractual clauses.
We ourselves never store your IP address in plain text.
4. Cookies
The website uses only technically necessary cookies. No consent is required for these (Section 25 (2) no. 2 of the German TDDDG), which is why there is no cookie banner.
- sb-…-auth-token (possibly in several parts): login session. Set only when you sign in. Duration: session, extended while in use.
- locale: remembers the language you chose. Duration: 1 year.
5. Database, sign-in and file storage (Supabase)
Accounts, orders, entitlements, reviews and the PDF files are stored with Supabase, Inc., 970 Toa Payoh North #07-04, Singapore 318992, in the Frankfurt am Main data centre (eu-central-1). Supabase sends the confirmation and password e-mails on our behalf. A data processing agreement is in place with Supabase.
5.1 Account
An account is required for purchases. The following is stored: e-mail address, password (exclusively as a hash, never in plain text), preferred language, time of registration. Purpose: access to purchased files. Legal basis: Art. 6 (1) (b) GDPR (performance of a contract). Retention: until the account is deleted.
5.2 Orders and entitlements
For a purchase we store: the product bought, amount, currency, time, the session and payment identifiers assigned by Stripe, and the resulting entitlement to retrieve the file (including any revocation in case of a refund). Purpose: performance of the contract, proof, refunds. Legal basis: Art. 6 (1) (b) GDPR; for retention, Art. 6 (1) (c) GDPR in conjunction with commercial and tax law retention obligations. Retention: 10 years after the end of the calendar year of the order (Section 147 of the German Fiscal Code, AO).
5.3 Download log
Every retrieval of a purchased file is logged: account, file, time and a hash of the IP address. The IP address itself is not stored; the hash cannot be reversed without our server's secret key. Purpose: detecting misuse, such as the sharing of access. Legal basis: Art. 6 (1) (f) GDPR (legitimate interest in protecting the content). Retention: 12 months.
5.4 Protection against misuse
Sign-in attempts, registrations, password e-mails, file retrievals, purchases and reviews are counted per sender in order to prevent automated password guessing and mass retrieval. Only a hash of the IP address and a counter are stored for this; expired counters are deleted within one hour. Legal basis: Art. 6 (1) (f) GDPR.
5.5 Reviews
If you write a review, we store the display name you chose, the text, the rating, the language, the product it refers to, the time, and whether a purchase existed at the time of writing. Reviews are read and approved by us before publication. Publicly visible are only display name, text, rating, date and the label "Verified purchase" or "No purchase". Your e-mail address is not published. Legal basis: Art. 6 (1) (a) GDPR (consent by submitting); you may request deletion at any time by e-mail.
6. Payment processing (Stripe)
Payments are processed by Stripe Payments Europe, Ltd., 1 Grand Canal Street Lower, Grand Canal Dock, Dublin, D02 H210, Ireland. You enter payment data (card number, bank details) exclusively on Stripe's page; our website never receives it. Stripe acts as the seller of the digital content and processes the data required for payment, tax and receipt under its own responsibility. Stripe's privacy policy applies: https://stripe.com/privacy
From Stripe we receive: confirmation of the payment, the identifiers of the payment and the purchase, and the e-mail address in order to assign the entitlement to your account.
7. E-mails
We send only e-mails that are necessary for use: confirmation of your e-mail address on registration and the link to reset your password. Receipts are sent by Stripe. We do not send marketing e-mails.
8. Contact by e-mail
If you write to us by e-mail, we process your details to handle the enquiry (Art. 6 (1) (b) or (f) GDPR). Messages are deleted once the enquiry is settled and no retention obligation exists.
9. Your rights
You have the right to access (Art. 15 GDPR), rectification (Art. 16), erasure (Art. 17), restriction of processing (Art. 18), data portability (Art. 20) and to object to processing based on legitimate interests (Art. 21). You may withdraw consent at any time with effect for the future.
An e-mail to business.algevia@gmail.com is sufficient. We delete your account on request; orders remain stored without reference to the account because of statutory retention obligations.
You also have the right to lodge a complaint with a data protection supervisory authority, for example the one responsible for your place of residence.
10. Security
The connection is encrypted throughout (HTTPS, HSTS). Purchased files can be retrieved only through short-lived signed addresses that expire after five minutes and are issued only after server-side verification of the entitlement. Passwords are stored exclusively as hashes.
11. Changes
We amend this policy when the website or the legal situation changes. The version published here applies.
This English version is provided for convenience. In case of doubt, the German version applies.