A kind of new distributed signcryption protocol was proposed based on the ideal vector space secret sharing scheme and the modified signcryption scheme of Zheng1.Without the involvement of a trusted key distribution center

this protocol could gain its ends of both threshold signature and threshold encryption simultaneously

however

its cost was equal to threshold signature only.Furthermore

based on the discrete logarithm

properties were verified and structured

the legitimacy of the participators could be confirmed during the processes of the keys generation

distributed signcryption and distributed unsigncryption

which prevented the participators cheating.