Sure. Schema:
type User @secret(field:"passwd") {
email: String! @id @search(by: [hash])
first_name: String @search(by: [hash])
last_name: String @search(by: [hash])
}
Mutation:
mutation {
addUser(input:[
{first_name:"John",last_name:"Doe",email:"user@domain.com",passwd:"secret"}
]) {numUids}
}