Tommaso Traetta

On circular external difference families

Circular external difference families (CEDFs) are a recently-introduced variation of external difference families (EDFs) with applications to non-malleable threshold schemes: a $(v,m,\ell,1)$-CEDF is an $m$-sequence $(A_0, \ldots, A_{m-1})$ of $\ell$-subsets of an additive group...

Characterizing Pyramidal Hadamard Designs With the Largest Number of Fixed Points

ABSTRACT A symmetric ‐design is said to be ‐pyramidal, with , under the action of a group if acts as an automorphism group fixing points and acting sharply transitively on the remaining ones. We show that, necessarily, . In particular, for a Hadamard design with parameters , for...