<A HREF="http://www.computing.surrey.ac.uk/personal/st/S.Schneider/papers/2011/cryptoforma11a.pdf">Cryptographic Protocols with Everyday Objects</A> (section 5)

> Typical cryptographic Secret Santa protocols require a fully
> homomorphic encryption system. These protocols are thus suitable for
> those with some planning, some expertise and access to computational
> assistance, but not to a group of friends without access to computers.
> Here we present an alternative solution, which does not lower the
> security requirements, and does not require anything beyond card,
> envelopes and pens.