Watermarking vs. Hashing
Two fundamental technologies for content protection—each with different strengths. Understanding when to use each (and why Stelais uses both) is key to effective content protection.
Summary: Cryptographic hashing proves the exact original content at a specific point in time—but only works for exact matches. Invisible watermarking embeds ownership data that survives modifications—but doesn't prove when content was created. Stelais combines both: hashing for proving the original, watermarking for tracing copies. Together, they provide complete protection.
What This Means
Detailed Comparison
| Aspect | Cryptographic Hash | Invisible Watermark |
|---|---|---|
| Primary purpose | Prove exact content at a point in time | Track ownership through modifications |
| Survives modifications | No—any change breaks the match | Yes—survives compression, cropping, etc. |
| Proves timestamp | Yes (when anchored to blockchain) | No—shows ownership, not when |
| Detects tampering | Yes—different hash means different content | No—designed to persist through changes |
| Traces copies | No—only matches exact original | Yes—ownership data in every copy |
| Best for | Proving the original existed | Claiming ownership of derivatives |
Why Stelais Uses Both
Content protection faces two distinct challenges that require different tools:
Challenge 1: Proving the Original
When someone claims they created something first, you need irrefutable proof that your version existed at a specific time.
Solution: Cryptographic hash + blockchain timestamp. The hash proves exactly what you registered, and the blockchain proves when.
Challenge 2: Tracing Copies
When your content is reposted, screenshot, compressed, or modified, hashes won't match. You need a way to prove the copy came from your original.
Solution: Invisible watermark. The embedded ownership data survives transformations and can be extracted from copies.
Complete Coverage
With both technologies, Stelais provides complete protection: the hash proves your original, and the watermark traces every copy back to you. Neither alone is sufficient—together, they cover all scenarios.
How Stelais Approaches This
When you register content with Stelais, both technologies are applied automatically:
- 1Upload content
Your original file is processed locally—it's never stored on our servers.
- 2Hash generated
A SHA-256 hash of your exact content is created—your permanent fingerprint.
- 3Watermark embedded
Invisible ownership data is encoded into your content using steganographic techniques.
- 4Anchored to blockchain
Your hash and proof data are permanently recorded on Arweave with an immutable timestamp.