  With the development of electric vehicles, more and more electric vehicles
have difficulties in parking and charging. One of the reasons is that the
number of charging piles is difficult to support the energy supply of electric
vehicles, and a large number of private charging piles have a long idle time,
so the energy supply problem of electric vehicles can be solved by sharing
charging piles. The shared charging pile scheme uses Paillier encryption scheme
and improved scheme to effectively protect user data. The scheme has
homomorphism of addition and subtraction, and can process information without
decryption. However, considering that different users have different needs, the
matching is carried out after calculating the needs put forward by users. This
scheme can effectively protect users' privacy and provide matching mechanisms
with different requirements, so that users can better match the appropriate
charging piles. The final result shows that its efficiency is better than the
original Paillier scheme, and it can also meet the security requirements.
