Authority Dashboard
Op'n Cezami
"It’s not about replacing paper certificates. It’s about proving what you’ve already done right."
Op'n Cezami is a modern system designed to help experts issue tamper-proof, cryptographically signed documents without abandoning the physical format.
The Solution: LegatoKey
We bind the physical and digital worlds via secure QR codes.
- ✓ A physical certificate to hold.
- ✓ Cryptographic proof your signature hasn't been faked.
- ✓ Verifiable by anyone via LegatoLink.
Trust & Technology Together
A new way to verify authenticity without losing the human touch.
The Digital Wax Seal
Think of it like the wax seals of old: a king’s ring pressed into hot wax proved the letter was genuine. Op'n-Czami does the same digitally:
Create Identity
Generate a unique digital signature.
Sign Document
Drag & drop to lock in a secure format.
Verify Instantly
Scan for a Green Check or Red X.
Makers & Experts
Protect your reputation by adding a digital signature for tamper-proof assurance.
Musicians & Collectors
Instant proof. Whether buying in Tokyo or New York, one scan confirms the document hasn’t been altered no forgery, no doubt, no delays
Open Source
No 'black boxes'. Trust is built on transparency. Anyone can audit the code.
Tour the Interface
Swipe to explore workflow
Transparent by Design
Self-sovereign • Open Source • "Don't Trust Verify"
No Vendor Lock-in
You stay independent. No forced subscriptions, no cloud dependencies. The software runs locally on your machine.
Universally Verifiable
Musicians can verify authenticity instantly using the free LegatoLink app even without internet access.
Image + Text Protected
Our cryptography covers visual content too. Proof that the photos on the certificate haven't been altered.
Core Edition
Always Free & Open Source (LGPL v3)
- ▪ Create cryptographically signed certificates
- ▪ Generate LegatoKey QR codes
- ▪ Full commercial or personal use
- ▪ Auditability: Inspect the code anytime
Power Tools
For High-Volume Ateliers & Institutions
- ✦ Batch Signing: Sign hundreds of certificates in minutes.
- ✦ Tamper-Evident Audit Trail: A local blockchain-like log for legal-grade evidence.
- ✦ Global Usage Insights: Geographic analytics on where your LegatoKeys are verified.
- ✦ Priority Support: Direct technical assistance.
About the Authors
Founded in 1978 by Andre Levi, A&F Levi Luthier has built a worldwide reputation for excellence in fine string instruments. Combining deep traditional craftsmanship with modern technology under the direction of Frederic Levi, we develop solutions that support musicians in preserving their instruments. Legato is the ecosystem designed to bring trust and transparency to this heritage.
Need help with design or integration?
We can help you streamline your workflow, design custom certificate layouts, or integrate LegatoKey into your existing branding.
Contact Frederic LM: andrelevi@ruederome.com