Uncertainty often arises around objects concerning the relevant qualities that determine their value in different markets. The existence of conventions of quality allows to reduce this uncertainty but these conventions can be used strategically. So, other resources must be mobilized to authenticate objects relying on sensed experience. In this contribution, we present first our model of expertise and we then adopt a historical perspective questioning the plurality of regimes of authenticity. This plurality depends on the conception of copying and on the dif-ferent ways of attributing authorship between law and social norms. These sources of variation have changed the resources mobilized in authentication and thus its mode of organization and legitimation. The growing importance of scientific and legal guarantees in the current exchanges of high-value goods reflects the creation of a market for authentication and raises the question of its regulation
