diff --git a/captcha.go b/captcha.go
new file mode 100644
index 0000000..3659b25
--- /dev/null
+++ b/captcha.go
@@ -0,0 +1,67 @@
+package main
+
+import (
+	"math/rand"
+	"os/exec"
+	"strings"
+)
+
+type Captcha struct {
+	Id       string   `json:"id"`
+	Imgs     []string `json:"imgs"`
+	Question string   `json:"question"`
+	Date     string   `json:"date"`
+}
+type CaptchaSolution struct {
+	Id           string   `json:"id"`
+	Imgs         []string `json:"imgs"`
+	ImgsSolution []string `json:"imgssolution"`
+	Question     string   `json:"question"`
+	Date         string   `json:"date"`
+}
+type ImgFakePath struct {
+	CaptchaId string `json:"captchaid"`
+	Real      string `json:"real"`
+	Fake      string `json:"fake"`
+}
+
+func generateUUID() string {
+	out, err := exec.Command("uuidgen").Output()
+	check(err)
+	uuid := string(out)
+	uuid = strings.Replace(uuid, "\n", "", -1)
+	return uuid
+}
+func generateRandInt(min int, max int) int {
+	//rand.Seed(time.Now().UTC().UnixNano())
+	return rand.Intn(max-min) + min
+}
+func generateCaptcha(count int) Captcha {
+	var captcha Captcha
+	var captchaSol CaptchaSolution
+
+	captcha.Id = generateUUID()
+	captchaSol.Id = captcha.Id
+
+	for i := 0; i < count; i++ {
+		nCateg := generateRandInt(0, len(categDataset))
+		nImg := generateRandInt(0, len(dataset[categDataset[nCateg]]))
+		//imgFakePath
+		var imgFakePath ImgFakePath
+		imgFakePath.CaptchaId = captcha.Id
+		imgFakePath.Real = categDataset[nCateg] + "/" + dataset[categDataset[nCateg]][nImg]
+		imgFakePath.Fake = generateUUID() + ".png"
+		err := imgFakePathCollection.Insert(imgFakePath)
+		check(err)
+		captcha.Imgs = append(captcha.Imgs, imgFakePath.Fake)
+		captchaSol.Imgs = append(captchaSol.Imgs, dataset[categDataset[nCateg]][nImg])
+		captchaSol.ImgsSolution = append(captchaSol.ImgsSolution, categDataset[nCateg])
+	}
+	captcha.Question = "Select all leopards"
+	captchaSol.Question = "Select all leopards"
+	err := captchaCollection.Insert(captcha)
+	check(err)
+	err = captchaSolutionCollection.Insert(captchaSol)
+	check(err)
+	return captcha
+}
diff --git a/imageOperations.go b/imageOperations.go
index 8af06b3..ea9a623 100644
--- a/imageOperations.go
+++ b/imageOperations.go
@@ -2,14 +2,27 @@ package main
 
 import (
 	"bytes"
+	"fmt"
 	"image"
+	"image/jpeg"
 	"image/png"
 )
 
-func dataToPNG(data []byte, imageName string) (image.Image, error) {
+func dataToImage(data []byte, imageExtension string) (image.Image, error) {
 	reader := bytes.NewReader(data)
-	img, err := png.Decode(reader)
+	//img, err := png.Decode(reader)
+	var img image.Image
+	var err error
+	switch imageExtension {
+	case "png":
+		img, err = png.Decode(reader)
+	case "jpg", "jpeg":
+		img, err = jpeg.Decode(reader)
+	default:
+		img = nil
+	}
 	if err != nil {
+		fmt.Println(err)
 		return img, err
 	}
 	return img, err
diff --git a/main.go b/main.go
index 98d85da..75a4970 100644
--- a/main.go
+++ b/main.go
@@ -2,7 +2,10 @@ package main
 
 import (
 	"log"
+	"math/rand"
 	"net/http"
+	"strconv"
+	"time"
 
 	"github.com/gorilla/handlers"
 )
@@ -10,11 +13,25 @@ import (
 func main() {
 	savelog()
 	log.Println("goCaptcha started")
+	rand.Seed(time.Now().UTC().UnixNano())
+
+	//connect with mongodb
+	readMongodbConfig("./mongodbConfig.json")
+	session, err := getSession()
+	check(err)
+	captchaCollection = getCollection(session, "captchas")
+	captchaSolutionCollection = getCollection(session, "captchassolutions")
+	imgFakePathCollection = getCollection(session, "imgfakepath")
 
 	//start the server
 	//http server start
 	readServerConfig("./serverConfig.json")
 
+	//read the filenames of the dataset
+	readDataset(serverConfig.ImgsFolder)
+	log.Println("dataset read")
+	log.Println("num of dataset categories: " + strconv.Itoa(len(dataset)))
+
 	log.Println("server running")
 	log.Print("port: ")
 	log.Println(serverConfig.ServerPort)
diff --git a/mongoConfig.go b/mongoConfig.go
new file mode 100644
index 0000000..bd02417
--- /dev/null
+++ b/mongoConfig.go
@@ -0,0 +1,51 @@
+package main
+
+import (
+	"encoding/json"
+	"fmt"
+	"io/ioutil"
+
+	mgo "gopkg.in/mgo.v2"
+)
+
+//MongoConfig stores the configuration of mongodb to connect
+type MongoConfig struct {
+	Ip       string `json:"ip"`
+	Database string `json:"database"`
+}
+
+var mongoConfig MongoConfig
+
+var captchaCollection *mgo.Collection
+var captchaSolutionCollection *mgo.Collection
+var imgFakePathCollection *mgo.Collection
+
+func readMongodbConfig(path string) {
+	file, e := ioutil.ReadFile(path)
+	if e != nil {
+		fmt.Println("error:", e)
+	}
+	content := string(file)
+	json.Unmarshal([]byte(content), &mongoConfig)
+}
+
+func getSession() (*mgo.Session, error) {
+	session, err := mgo.Dial("mongodb://" + mongoConfig.Ip)
+	if err != nil {
+		panic(err)
+	}
+	//defer session.Close()
+
+	// Optional. Switch the session to a monotonic behavior.
+	session.SetMode(mgo.Monotonic, true)
+
+	// Optional. Switch the session to a monotonic behavior.
+	session.SetMode(mgo.Monotonic, true)
+
+	return session, err
+}
+func getCollection(session *mgo.Session, collection string) *mgo.Collection {
+
+	c := session.DB(mongoConfig.Database).C(collection)
+	return c
+}
diff --git a/mongodbConfig.json b/mongodbConfig.json
new file mode 100644
index 0000000..bd81350
--- /dev/null
+++ b/mongodbConfig.json
@@ -0,0 +1,4 @@
+{
+    "ip": "127.0.0.1",
+    "database": "goCaptcha"
+}
diff --git a/readDataset.go b/readDataset.go
new file mode 100644
index 0000000..c3bb50b
--- /dev/null
+++ b/readDataset.go
@@ -0,0 +1,21 @@
+package main
+
+import (
+	"io/ioutil"
+)
+
+var dataset map[string][]string
+var categDataset []string
+
+func readDataset(path string) {
+	dataset = make(map[string][]string)
+
+	folders, _ := ioutil.ReadDir(path)
+	for _, folder := range folders {
+		categDataset = append(categDataset, folder.Name())
+		folderFiles, _ := ioutil.ReadDir(path + "/" + folder.Name())
+		for _, file := range folderFiles {
+			dataset[folder.Name()] = append(dataset[folder.Name()], file.Name())
+		}
+	}
+}
diff --git a/serverRoutes.go b/serverRoutes.go
index a455080..01053bc 100644
--- a/serverRoutes.go
+++ b/serverRoutes.go
@@ -6,6 +6,9 @@ import (
 	"image/jpeg"
 	"io/ioutil"
 	"net/http"
+	"strings"
+
+	"gopkg.in/mgo.v2/bson"
 
 	"github.com/gorilla/mux"
 )
@@ -43,12 +46,20 @@ func GetImage(w http.ResponseWriter, r *http.Request) {
 	vars := mux.Vars(r)
 	imageName := vars["imageName"]
 
-	file, err := ioutil.ReadFile(serverConfig.ImgsFolder + "/" + imageName)
+	imgFakePath := ImgFakePath{}
+	err := imgFakePathCollection.Find(bson.M{"fake": imageName}).One(&imgFakePath)
+	check(err)
+
+	fmt.Println(serverConfig.ImgsFolder + "/" + imgFakePath.Real)
+
+	file, err := ioutil.ReadFile(serverConfig.ImgsFolder + "/" + imgFakePath.Real)
 	if err != nil {
 		fmt.Fprintln(w, err)
 	}
 
-	img, err := dataToPNG(file, imageName)
+	pathSplited := strings.Split(imgFakePath.Real, ".")
+	imageExtension := pathSplited[len(pathSplited)-1]
+	img, err := dataToImage(file, imageExtension)
 
 	if err != nil {
 		fmt.Fprintln(w, "image "+imageName+" does not exist in server")
@@ -58,7 +69,7 @@ func GetImage(w http.ResponseWriter, r *http.Request) {
 }
 func GetCaptcha(w http.ResponseWriter, r *http.Request) {
 
-	resp := ""
+	resp := generateCaptcha(6)
 	jsonResp, err := json.Marshal(resp)
 	check(err)
 	fmt.Fprintln(w, string(jsonResp))