Privacy

This site is run by Solve Algorithms Inc., trading as Solve Algorithms, contactable at contact@solvealgorithms.com — the data controller for everything below. A postal address is available on request and is given on every invoice.

What is collected

If you buy the book, the payment is handled by Stripe, who take your name, email, billing country and card details under their own privacy policy. Your card number never reaches this site or its servers, because Stripe collects it directly. We keep only Stripe’s customer reference, the amount, the date and the country, because tax law requires us to.

If you give us your email for the sample, we store your address and nothing else, to send you the sample and to tell you when the book is updated. Unsubscribe from any email and the address is deleted.

If you create a free account, we store your email address, a one-way hash of your password (never the password itself), and which parts of the online edition you have opened, so the book can reopen where you stopped. Delete your account and all of it goes with it, except the payment record above, which tax law requires us to keep for six years.

We run no advertising and no cross-site trackers. Visits are counted by Cloudflare Web Analytics, which sets no cookies, stores no personal data and cannot follow you to another site. If you have an account, one cookie keeps you signed in; it does nothing else, and there is no cookie at all until you sign in.

Your rights

You can ask what we hold about you, ask for it to be corrected, or ask for it to be deleted, by writing to contact@solvealgorithms.com. Under UK and EU data protection law we will answer within one month.

Readers who have asked not to be contacted are honoured permanently, including anyone who unsubscribed or withdrew consent under GDPR before this policy existed.