  This article studies the synchronization power of AllowList and DenyList
objects under the lens provided by Herlihy's consensus hierarchy. It specifies
AllowList and DenyList as distributed objects and shows that while they can
both be seen as specializations of a more general object type, they inherently
have different synchronization properties. While the AllowList object does not
require synchronization between participating processes, a DenyList object
requires processes to reach consensus on a specific set of processes. These
results are then applied to the analysis of anonymity-preserving systems that
use AllowList and DenyList objects. First, a blind-signature-based e-voting is
presented. Then DenyList and AllowList objects are used to determine the
consensus number of a specific decentralized key management system. Finally, an
anonymous money transfer protocol using the association of AllowList and
DenyList objects is studied.
