Pairings from a tensor product point of view
This work provides a foundational framework for pairings in cryptography, potentially enabling new applications, but it is incremental as it extends existing mathematical concepts to broader contexts.
The paper tackles the problem of constructing pairings (bilinear maps) on abelian groups beyond elliptic curves by using tensor products, showing that a pairing on A×A is always possible for any finite abelian group A. It proposes new constructions based on group duality and non-degeneracy.
Pairings are particular bilinear maps, and as any bilinear maps they factor through the tensor product as group homomorphisms. Besides, nothing seems to prevent us to construct pairings on other abelian groups than elliptic curves or more general abelian varieties. The point of view adopted in this contribution is based on these two observations. Thus we present an elliptic curve free study of pairings which is essentially based on tensor products of abelian groups (or modules). Tensor products of abelian groups are even explicitly computed under finiteness conditions. We reveal that the existence of pairings depends on the non-degeneracy of some universal bilinear map, called the canonical bilinear map. In particular it is shown that the construction of a pairing on $A\times A$ is always possible whatever a finite abelian group $A$ is. We also propose some new constructions of pairings, one of them being based on the notion of group duality which is related to the concept of non-degeneracy.