We were explaining here last week, that is to say represented by digital tokens placed on the blockchain. This technology is often presented as forgery-proof, it is even its greatest asset. In reality, the blockchain protects against the risk of double spending: a digital token cannot be spent twice at the same time. Likewise, we cannot transfer the same bitcoin to two people simultaneously. All users would see it immediately. But does blockchain also protect when a real asset is excessively (and fraudulently) tokenized? That is to say when title deeds representing part of a Ferrari or a building are issued in greater numbers than expected, and, of course, incognito.