The certificate

What is the certificate?

This is the passport of your item: a document signed by an expert recognized at European level and tamper-proof. It takes the form of a steel card. This card provides access at any time to a detailed certificate with 73 control points, high definition photos taken in a workshop. Everything is signed by an approved expert.

What material is the card made of?

It is made of brushed steel and weighs 33 grams. It guarantees instant access to the certificate on a protected address. Our choice was to make it in a durable material so that in case of sale, you give this card to the new owner. In case of loss, the data is saved and we are able to reissue your card.

How is this certificate tamper-proof?

No one can modify the data of your article because the certificate is registered in a decentralized and indelible database – the blockchain.

What does the small square on my certificate mean?

This is a QR code that can be used to instantly verify any documentation provided by Woltz & Welstein. You just need to scan it with your smartphone’s camera to be automatically redirected to the certificate.

What name will appear on the certificate?

By default, we will display the name of the person who made the payment. However, if you would prefer otherwise, you can ask us to do so.

What does the certificate look like?

You can see a preview of the Certificate of Authenticity here.


How are you going to remedy the counterfeiting?

First of all, we register and secure the serial number in a tamper-proof database. We check a minimum of 45 control points on each item. Finally, after the analysis, the expert gives his opinion and finalizes the certificate.

How can you be sure that the certificate will not be forged?

The certificate as well as the metal card are in the name of the owner of the article. As the counterfeiter cannot have the same first and last name as the owner, it thus becomes impossible to forge the certificate.

Can an expert validate a counterfeit item?

No, because its analysis is systematically verified by a second expert. It is therefore not possible for a single expert to validate a certificate.

Comment l’utilisez-vous la blockchain ?

Cette technologie n’est qu’une partie de la solution, notre travail est d’organiser la remontée de l’information, de la normaliser, de piloter le réseau des intervenants. Enfin, nous matérialisons cette technologie impalpable par une carte physique, facile à utiliser et infalsifiable.


What if their analysis turns out to be wrong?

We stake our reputation on each authentication, which is why at least two qualified professionals will be responsible for analyzing your article. If despite this our assessment turns out to be incorrect, we will reimburse you for the checked item at new value.

Why trust these experts?

At Woltz & Welstein, we carry out a strict selection before any hiring or collaboration based on the skills of each stakeholder. We put them through rigorous testing to determine their ability to perform hard authentication. Also, they commit their name and therefore their reputation on each certificate.

Who are the experts?

They are professionals recognized at European level and approved by the state. Most of them have more than ten years of experience in authentication.

The philosophy

Why buy an item with a certificate?

To ensure authenticity and obtain a detailed analysis of each item and proof of its market value, useful in the event of theft or loss. This is the only certificate combining high definition photos, with at least 45 points checked ensuring the authenticity and condition of the item. This is signed by 2 complementary professionals and recorded in a tamper-proof database.

Why did you create your authentication service?

In order to find a solution against fraud, and to facilitate the purchase of second-hand valuable items. We want to offer a standard that brings transparency and peace of mind during transactions.

Is it risky to buy a second-hand item?

Counterfeiting has become commonplace. Our statistics, concerning last September for example, were final with, on the advertisements posted by individuals, approximately 1 article in 3 turning out to be a counterfeit. This is a very real and topical problem.


What is an authentication token?

The authentication token is used to check the authenticity of an article analyzed by Woltz & Welstein from a simple smartphone.

What does the authentication token look like?

We have several types of authentication tokens, each suitable for authenticated products. They can be the size of a coin so they can easily slip into your favorite it bag, or much thinner to fit into a watch.

What technological innovation is there behind the card?

In short, traceability. Indeed, the certificate allows data to be traced from the inspection of the article online or in the workshop, through the validation of the expert, to its registration in the blockchain.

What will the blockchain bring?

Tamper-proof data. The blockchain is a non-centralized database: information is recorded at different levels, and this, indelibly. We cannot therefore modify the data. This is a recognized technology in various fields, including crypto currencies, we use it as a highly secure database.

The other documents

Is an archival extract of the mark better than this certificate?

The extract from the archives is an informative document, but not an expert report, it does not prove the authenticity or the value of the article. It is however precious, moreover, if the seller has it, it is digitized in the certificate to be always accessible.

Is an invoice from a seller sufficient?

The invoice indicates the sale price and the name of the professional. Our certificate includes these elements, adding high definition photos, details of the minimum 45 control points, specifying the condition and authenticity, a date estimate, serial number, etc. It is signed by a recognized expert and recorded in a tamper-proof database.

In the second hand, why don’t brands themselves authenticate the items?

It’s not their job. Some manufacturers are willing to verify their product, but they don’t necessarily have the resources or the organization to do it at scale.

Why is this certificate not at the initiative of the brands?

More and more brands are issuing digital certificates, but there is no common standard yet.

Use cases

Is this certificate only useful for rare items?

It is always useful, regardless of the article. It protects it and serves as proof of its value in the event of theft or during its sale.

Is the certificate an additional cost if you are looking for a good deal?

This certificate is an infallible protection to avoid losing your investment. The statistics are alarming, especially on modern Rolexes or Louis Vuitton bags. On well-known sales sites, the number of fakes is overwhelming.

How do you make sure a vintage item is authentic?

With vintage, every element impacts the price. To avoid unpleasant surprises, our certificate is the only one to detail all the elements that may have been replaced during a lifetime. It details for each the condition as well as the authenticity, supporting photos.

How does the certificate protect me?

We secure your item’s unique serial number in a tamper-proof database, to prevent malicious sellers from spoofing this number. In addition to the serial number, a minimum of 45 control points are listed, with high-definition photographs. The card proves the existence of your item, its authenticity and its market value – essential proofs in the context of a report of theft to insurance. Finally, the card gives you access to a Breakage / Theft insurance offer reserved exclusively for the owners of the certificate, which covers accidents and theft, including those outside the home.

If I lose the metal card, what happens?

Rest assured, your data is in a safe place. We cancel the old card and replace it for € 29.

What happens if I sell my item?
The map follows the article throughout its life. If you sell your item, let us know so that we record the transfer – it’s free – we cancel the old card and replace it for € 29


Our specialists will review your submission and provide preliminary estimates.


20 Rockefeller Plaza, New York, NY 10020


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