Privacy Policy

This policy applies to cipher9books.com, operated by Cipher 9 Publishing. The site is a book catalog, puzzle experience, and information service. Amazon—not Cipher 9 Publishing—processes purchases reached through our buy links.

When you contact us, we receive your name, email address, inquiry category, message, and the page from which you contacted us. When you request the newsletter, we receive your email address, selected interests, consent record, signup page, and confirmation status. When you request a free sampler, we use your email address to deliver it, then retain a one-way hash of the address with the sampler choice, delivery status, and download count for abuse prevention and aggregate measurement.

With your permission, our first-party analytics records a pseudonymous visitor and session identifier, pages and interactions, referring page and campaign parameters, browser/device information, and approximate location supplied by our hosting platform (such as country, region, or city). Analytics events are designed not to contain your email, message, password, or payment information.

We use contact information to answer requests; sampler information to deliver the PDF you requested and prevent abuse; newsletter information to send communications you explicitly requested; analytics to improve our catalog and puzzle experiences; and limited technical information to protect the service. Our legal bases, where applicable, are your consent, steps taken at your request, and our legitimate interests in operating and securing the site. You may withdraw consent at any time.

Submitting the newsletter form does not immediately add you to the active list. We email a one-use confirmation link that expires after 24 hours, and the address becomes active only after you confirm. Every newsletter includes an unsubscribe option. Pending requests that are not confirmed are removed after 30 days.

For visitors in the EU/EEA, United Kingdom, Switzerland, or where location cannot be determined, optional analytics remain off until permission is given. In other regions, privacy-friendly first-party analytics are enabled by default, subject to local requirements. If enabled, a pseudonymous visitor identifier may remain for up to 400 days, while session identifiers expire after about 30 minutes. Analytics records are retained for up to 14 months. We do not use advertising cookies on this site.

Review cookie preferences. Choosing “Necessary only” removes our analytics identifiers from your browser and prevents new analytics events from being sent.

We use Vercel for website hosting and delivery, Cloudflare for authoritative DNS, Neon for managed PostgreSQL records, and either Resend or Google's Gmail/SMTP service for email delivery, depending on the configured route. Amazon handles purchases and its own customer records. These providers process only the information needed to supply their services and may process data outside your country under their own safeguards.

Active newsletter records remain until you unsubscribe or ask us to delete them; a limited suppression record may be retained to honor an unsubscribe request. Sampler delivery links expire after 7 days, and sampler request records retain only a one-way email hash rather than the address itself for up to 14 months. Contact correspondence is normally removed when no longer needed and within 24 months. Analytics records are removed after 14 months. We use access controls, encrypted transport, one-use hashed confirmation tokens, and reasonable operational safeguards, but no online service can guarantee absolute security.

Depending on where you live, you may request access, correction, deletion, restriction, portability, or objection to certain processing; withdraw consent; or complain to your local data-protection authority. California residents may also request to know, correct, or delete covered information and receive equal service for exercising a right. We do not sell or share personal information for cross-context behavioral advertising.

Amazon processes payment, shipping, and order information under its privacy notice. Cipher 9 Publishing does not receive or store your payment-card or shipping information from Amazon orders.

This service is not directed to children under 13, and we do not knowingly collect their personal information. To exercise a right or ask a privacy question, email support@cipher9books.com or use our contact page. We may ask for information needed to verify a request before acting on it.