The Problem
When you download a Linux ISO, best practice says to verify the hash.
You compute the SHA256 of your download, compare it to the hash on the
official website, and if they match — you're good. Right?
Not quite.
If an attacker compromises a download server, they can also update the
hash page. You'd download a malicious ISO, verify it against the
malicious hash, and everything would appear "verified."
Download ISO from Site A → Get hash from Site A → Compare → "Verified" ✓
But if Site A is compromised:
Download MALICIOUS ISO → Get MATCHING malicious hash → Compare → "Verified" ✓
This is circular trust, and it's a real gap in supply chain security.
The Solution
HashWatch™ independently crawls official ISO repositories and stores hashes
with timestamps. When you verify a hash here, you're checking against a
third-party record — not the same source you downloaded from.
We track:
- When a hash was first seen
- How long it's been stable
- Any changes over time
- Community reports of mismatches
Who This Is For
HashWatch™ is built for people who actually care about verifying their downloads:
- Security professionals installing Kali, Parrot, or other pen-testing distros
- Linux gamers grabbing Nobara, Bazzite, or other gaming-focused ISOs
- Privacy-conscious users downloading Tails or Whonix
- Sysadmins deploying Ubuntu, Debian, Rocky, or Alma in production
- Anyone who understands that "verify the hash" has a trust problem
Request a Distro
Don't see your distro? We're always expanding coverage.
Request a Distro
For Distro Maintainers
If you maintain a Linux distribution and want to:
- Verify your hashes are correct in our database
- Report a legitimate hash change (new release, security update)
- Request priority tracking for your distro
- Dispute a "suspicious" flag on a hash change
Contact us at security@databaysolutions.com
Please email from your official project domain or include a link to a signed statement
on your official site/repo. We're not going to update our records based on a random Gmail.
About Databay LLC
HashWatch™ is an R&D project from Databay LLC,
a technology company focused on building practical solutions to real problems.
This project was born from a simple realization while installing Parrot OS:
"If someone compromised this download, they'd update the hash page too."
A quick search confirmed that no independent hash verification service existed.
So we built one.
Built on the line, not in the boardroom.