Deliver a password protected files



Since i’m new to fiverr i need to know how to deal with buyers who doesn’t communicate much through order time.

recently i got a 150$ order for revamping some mobile app UI’s. buyer from Mexico. he just place the order without contact me. he just simply mention what he want to do. i think many times i tried to had a proper conversation with him but I only get few replies.

now I have to deliver the order but i’m doubting that what if he take my deliver files and refuse the payment. so i thought to send encrypted deliver file. after he complete his payment i will send the password to him.

what i want to know is I can do it in that way ? fiverr allows to send encrypted file to buyer and when buyer complete his payments seller will send the password.

please help me guys