  Semi-quantum secret sharing (SQSS) is an important branch of semi-quantum
cryptography, and differs from quantum secret sharing (QSS) in that not all
parties are required to possess quantum capabilities. All previous SQSS
protocols have three common features: (1) they adopt product states or
entangled states as initial quantum resource; (2) the particles prepared by
quantum party are transmitted in a tree-type way; and (3) they require the
classical parties to possess the measurement capability. In this paper, two
circular SQSS protocols with single particles are suggested, where the first
one requires the classical parties to possess the measurement capability while
the second one does not have this requirement. Compared with the previous SQSS
protocols, the proposed SQSS protocols have some distinct features: (1) they
adopt single particles rather than product states or entangled states as
initial quantum resource; (2) the particles prepared by quantum party are
transmitted in a circular way; and (3) the second protocol releases the
classical parties from the measurement capability. The proposed SQSS protocols
are robust against some famous attacks from an eavesdropper, such as the
measure-resend attack, the intercept-resend attack and the entangle-measure
attack, and are feasible with present quantum technologies in reality.
