Privacy Policy

Hush is built and operated by the Umikflow team. This Privacy Policy explains how Hush handles information.

Your Data

Encrypted Secrets

Hush is designed so that secret contents are encrypted locally in your browser before they are sent to our servers. Hush does not receive or store the decryption key.

Limited Metadata

Hush temporarily stores encrypted envelope fields, including ciphertext, IV, and—where applicable—a salt and wrapped key. We also store an opaque secret ID, an expiry timestamp, and a hashed finalization token for passphrase-protected secrets.

Anti-Abuse Data

To prevent abuse, Hush uses HMAC-hashed IP identifiers for rate limiting. These identifiers are retained only within the applicable 15-minute and 24-hour rate-limit windows. Raw IP addresses are not stored in Hush's application database.

Deletion Guarantees & Limits

One-Time Mode vs Passphrase Mode

For normal secrets, after a recipient deliberately clicks Reveal, the encrypted envelope is consumed and erased in a single database transaction. A later request for the same secret is unavailable.

Passphrase mode works differently. An incorrect passphrase can be retried. The encrypted envelope remains available until the recipient successfully decrypts it and the official client completes finalization, or until the secret expires. This is best-effort finalization rather than the same server-enforced one-time mechanism used by normal secrets.

Expiry and Cleanup

Expired secrets are denied access immediately based on their expiry timestamp. A scheduled cleanup process deletes expired records from the live database.

Deletion from the live database does not necessarily mean immediate removal from all infrastructure backups. We rely on cloud providers for infrastructure and do not claim that provider backups are instantly purged after a record is deleted.

Advertising & Third-Party Analytics

To support infrastructure costs, Hush displays advertisements exclusively on select public informational pages (such as the homepage, guides, and educational articles).

Route-Level Advertising and Analytics Isolation

Hush application code is designed to prevent ad and analytics requests on protected secret and room routes, including:

• One-time secret reading, decrypting, and viewing routes (/s/*)
• Private room generation (/rooms) and active room chat routes (/r/*)
• Application API endpoints (/api/*) and unavailable error states

Decryption keys (stored in URL fragments), secret IDs, room IDs, passphrases, encrypted payloads, and decrypted message text are not sent to advertising or analytics providers.

Advertising Providers & Data Processing

• Google AdMob (Android App): Used to deliver advertisements (such as anchored adaptive banners, native article cards, occasional app open displays on cold launch, and creation transitions) strictly on approved public screens. The Google Mobile Ads SDK may collect and process device identifiers (including Android Advertising ID / AAID), coarse/approximate location derived from IP address, and ad interaction analytics under Google's Privacy Policy. All secret, private room, and decryption routes remain strictly ad-free.
• Google AdSense (Web): When configured on public web pages, Google AdSense uses cookies and device identifiers to serve, personalize, and measure ad performance.
• Vercel Web Analytics: Privacy-friendly, aggregate page analytics running solely on public informational pages. All secret, private room, API, and error route URLs (/s/*, /r/*, /rooms, /api/*, /unavailable) are permanently dropped prior to event transmission.

Consent & User Controls

In the European Economic Area (EEA), United Kingdom, and Switzerland:

• On Android, the Google User Messaging Platform (UMP) prompts for user consent prior to requesting ads. If consent is declined, no ad requests are made.
• On the Web, ad delivery respects Consent Management Platform (CMP) choices.
• Android users can reset or delete their device Advertising ID at any time in Android Settings > Google > Ads.

Service Providers

We rely on the following infrastructure providers to operate Hush:

• Supabase: Database hosting, rate-limiting logic, and scheduled cleanup jobs.
• Cloudflare Turnstile: Bot and automated-abuse prevention during secret creation.
• Google (AdMob / AdSense): Advertising services on approved public informational pages.
• Vercel: Web hosting and public-route web analytics.

These providers may process limited technical connection data under their own privacy policies.

Contact

For privacy questions or requests, contact support@umikflow.com.