main.go

package main

import (
	"bytes"
	"log"
	"math/rand"

	"checklist/pir"
)

// Generate a database filled with random bytes
func randomDatabase(nRows int, rowLen int) *pir.StaticDB {
	rows := make([]pir.Row, nRows)
	for i := 0; i < nRows; i++ {
		rows[i] = make(pir.Row, rowLen)
		_, err := rand.Read(rows[i][:])
		if err != nil {
			log.Fatal("rand.Read failed")
		}
	}

	return pir.StaticDBFromRows(rows)
}

func main() {
	// Use the puncturable-set-based PIR scheme
	pirType := pir.Punc

	nRows := 1024
	rowLen := 256
	queryRow := 79

	// Generate a database
	db := randomDatabase(nRows, rowLen)

	// ===== OFFLINE PHASE =====
	//    Client asks for offline hint
	offlineReq := pir.NewHintReq(pir.RandSource(), pirType)

	//    Server responds with hint
	offlineResp, err := offlineReq.Process(*db)
	if err != nil {
		log.Fatal("Offline hint generation failed")
	}

	// Initialize the client state
	client := offlineResp.(pir.HintResp).InitClient(pir.RandSource())

	// ===== ONLINE PHASE =====
	//    Client generates queries for servers
	queries, recon := client.Query(queryRow)

	//    Servers answer queries
	answers := make([]interface{}, len(queries))
	for i := 0; i < len(queries); i++ {
		answers[i], err = queries[i].Process(*db)
		if err != nil {
			log.Fatal("Error answering query")
		}
	}

	//    Client reconstructs
	row, err := recon(answers)
	if err != nil {
		log.Fatal("Could not reconstruct")
	}

	if !bytes.Equal(row, db.Row(queryRow)) {
		log.Fatal("Incorrect answer returned")
	}
}