diff --git a/go.mod b/go.mod
index cf79ef7..f589ab7 100644
--- a/go.mod
+++ b/go.mod
@@ -5,10 +5,11 @@ go 1.17
 require (
 	github.com/asaskevich/govalidator v0.0.0-20210307081110-f21760c49a8d
 	github.com/evanphx/json-patch v0.5.2
-	github.com/free5gc/openapi v1.0.7-0.20231216094313-e15a4ff046f6
+	github.com/free5gc/openapi v1.0.7-0.20240117084712-52ad99299693
 	github.com/free5gc/util v1.0.5-0.20231001095115-433858e5be94
 	github.com/gin-gonic/gin v1.9.1
 	github.com/google/uuid v1.3.0
+	github.com/pkg/errors v0.9.1
 	github.com/sirupsen/logrus v1.8.1
 	github.com/urfave/cli v1.22.5
 	gopkg.in/yaml.v2 v2.4.0
@@ -36,7 +37,6 @@ require (
 	github.com/modern-go/concurrent v0.0.0-20180306012644-bacd9c7ef1dd // indirect
 	github.com/modern-go/reflect2 v1.0.2 // indirect
 	github.com/pelletier/go-toml/v2 v2.0.8 // indirect
-	github.com/pkg/errors v0.9.1 // indirect
 	github.com/russross/blackfriday/v2 v2.0.1 // indirect
 	github.com/shurcooL/sanitized_anchor_name v1.0.0 // indirect
 	github.com/tim-ywliu/nested-logrus-formatter v1.3.2 // indirect
diff --git a/go.sum b/go.sum
index 7c7251a..779caed 100644
--- a/go.sum
+++ b/go.sum
@@ -60,10 +60,8 @@ github.com/envoyproxy/go-control-plane v0.9.4/go.mod h1:6rpuAdCZL397s3pYoYcLgu1m
 github.com/envoyproxy/protoc-gen-validate v0.1.0/go.mod h1:iSmxcyjqTsJpI2R4NaDN7+kN2VEUnK/pcBlmesArF7c=
 github.com/evanphx/json-patch v0.5.2 h1:xVCHIVMUu1wtM/VkR9jVZ45N3FhZfYMMYGorLCR8P3k=
 github.com/evanphx/json-patch v0.5.2/go.mod h1:ZWS5hhDbVDyob71nXKNL0+PWn6ToqBHMikGIFbs31qQ=
-github.com/free5gc/openapi v1.0.7-0.20231112094355-a96c3450377e h1:mXnoioq+fxpChliDl5Uy+m6+Hm7iWrJPZo9mi6BijHE=
-github.com/free5gc/openapi v1.0.7-0.20231112094355-a96c3450377e/go.mod h1:qv9KqEucoZSeENPRFGxfTe+33ZWYyiYFx1Rj+H0DoWA=
-github.com/free5gc/openapi v1.0.7-0.20231216094313-e15a4ff046f6 h1:8P/wOkTAQMgZJe9pUUNSTE5PWeAdlMrsU9kLsI+VAVE=
-github.com/free5gc/openapi v1.0.7-0.20231216094313-e15a4ff046f6/go.mod h1:qv9KqEucoZSeENPRFGxfTe+33ZWYyiYFx1Rj+H0DoWA=
+github.com/free5gc/openapi v1.0.7-0.20240117084712-52ad99299693 h1:gFyYBsErQAkx4OVHXYqjO0efO9gPWydQavQcjU0CkHY=
+github.com/free5gc/openapi v1.0.7-0.20240117084712-52ad99299693/go.mod h1:qv9KqEucoZSeENPRFGxfTe+33ZWYyiYFx1Rj+H0DoWA=
 github.com/free5gc/util v1.0.5-0.20231001095115-433858e5be94 h1:tNylIqH/m5Kq+3KuC+jjXGl06Y6EmM8yq61ZUgNrPBY=
 github.com/free5gc/util v1.0.5-0.20231001095115-433858e5be94/go.mod h1:aMszJZbCkcg5xaGgzya+55jz+OPMsJqPLq5Z3fWDFPE=
 github.com/gabriel-vasile/mimetype v1.4.2 h1:w5qFW6JKBz9Y393Y4q372O9A7cUSequkh1Q7OhCmWKU=
diff --git a/internal/context/context.go b/internal/context/context.go
index 48564e7..5899b1e 100644
--- a/internal/context/context.go
+++ b/internal/context/context.go
@@ -43,6 +43,12 @@ func Init() {
 	nssfContext.NrfUri = fmt.Sprintf("%s://%s:%d", models.UriScheme_HTTPS, nssfContext.RegisterIPv4, 29510)
 }
 
+type NFContext interface {
+	AuthorizationCheck(token, serviceName string) error
+}
+
+var _ NFContext = &NSSFContext{}
+
 type NSSFContext struct {
 	NfId         string
 	Name         string
@@ -130,12 +136,22 @@ func GetSelf() *NSSFContext {
 	return &nssfContext
 }
 
-func (c *NSSFContext) GetTokenCtx(scope, targetNF string) (
+func (c *NSSFContext) GetTokenCtx(scope string, targetNF models.NfType) (
 	context.Context, *models.ProblemDetails, error,
 ) {
 	if !c.OAuth2Required {
 		return context.TODO(), nil, nil
 	}
-	return oauth.GetTokenCtx(models.NfType_NSSF,
-		c.NfId, c.NrfUri, scope, targetNF)
+	return oauth.GetTokenCtx(models.NfType_NSSF, targetNF,
+		c.NfId, c.NrfUri, scope)
+}
+
+func (c *NSSFContext) AuthorizationCheck(token, serviceName string) error {
+	if !c.OAuth2Required {
+		logger.UtilLog.Debugf("NSSFContext::AuthorizationCheck: OAuth2 not required\n")
+		return nil
+	}
+
+	logger.UtilLog.Debugf("NSSFContext::AuthorizationCheck: token[%s] serviceName[%s]\n", token, serviceName)
+	return oauth.VerifyOAuth(token, serviceName, c.NrfCertPem)
 }
diff --git a/internal/sbi/consumer/nf_management.go b/internal/sbi/consumer/nf_management.go
index 8f5e3e2..1274e46 100644
--- a/internal/sbi/consumer/nf_management.go
+++ b/internal/sbi/consumer/nf_management.go
@@ -93,7 +93,7 @@ func SendDeregisterNFInstance() (*models.ProblemDetails, error) {
 
 	var err error
 
-	ctx, pd, err := nssf_context.GetSelf().GetTokenCtx("nnrf-nfm", "NRF")
+	ctx, pd, err := nssf_context.GetSelf().GetTokenCtx("nnrf-nfm", models.NfType_NRF)
 	if err != nil {
 		return pd, err
 	}
diff --git a/internal/sbi/nssaiavailability/routers.go b/internal/sbi/nssaiavailability/routers.go
index 27cc22a..ee285f7 100644
--- a/internal/sbi/nssaiavailability/routers.go
+++ b/internal/sbi/nssaiavailability/routers.go
@@ -15,11 +15,16 @@ import (
 
 	"github.com/gin-gonic/gin"
 
+	nssf_context "github.com/free5gc/nssf/internal/context"
 	"github.com/free5gc/nssf/internal/logger"
+	"github.com/free5gc/nssf/internal/util"
 	"github.com/free5gc/nssf/pkg/factory"
+	"github.com/free5gc/openapi/models"
 	logger_util "github.com/free5gc/util/logger"
 )
 
+const serviceName string = string(models.ServiceName_NNSSF_NSSAIAVAILABILITY)
+
 // Route is the information for every URI.
 type Route struct {
 	// Name is the name of this Route.
@@ -45,6 +50,11 @@ func NewRouter() *gin.Engine {
 func AddService(engine *gin.Engine) *gin.RouterGroup {
 	group := engine.Group(factory.NssfNssaiavailResUriPrefix)
 
+	routerAuthorizationCheck := util.NewRouterAuthorizationCheck(serviceName)
+	group.Use(func(c *gin.Context) {
+		routerAuthorizationCheck.Check(c, nssf_context.GetSelf())
+	})
+
 	for _, route := range routes {
 		switch route.Method {
 		case "GET":
diff --git a/internal/sbi/nsselection/routers.go b/internal/sbi/nsselection/routers.go
index 43fd1cb..c347505 100644
--- a/internal/sbi/nsselection/routers.go
+++ b/internal/sbi/nsselection/routers.go
@@ -15,11 +15,16 @@ import (
 
 	"github.com/gin-gonic/gin"
 
+	nssf_context "github.com/free5gc/nssf/internal/context"
 	"github.com/free5gc/nssf/internal/logger"
+	"github.com/free5gc/nssf/internal/util"
 	"github.com/free5gc/nssf/pkg/factory"
+	"github.com/free5gc/openapi/models"
 	logger_util "github.com/free5gc/util/logger"
 )
 
+const serviceName string = string(models.ServiceName_NNSSF_NSSELECTION)
+
 // Route is the information for every URI.
 type Route struct {
 	// Name is the name of this Route.
@@ -45,6 +50,11 @@ func NewRouter() *gin.Engine {
 func AddService(engine *gin.Engine) *gin.RouterGroup {
 	group := engine.Group(factory.NssfNsselectResUriPrefix)
 
+	routerAuthorizationCheck := util.NewRouterAuthorizationCheck(serviceName)
+	group.Use(func(c *gin.Context) {
+		routerAuthorizationCheck.Check(c, nssf_context.GetSelf())
+	})
+
 	for _, route := range routes {
 		switch route.Method {
 		case "GET":
diff --git a/internal/util/router_auth_check.go b/internal/util/router_auth_check.go
new file mode 100644
index 0000000..1943d64
--- /dev/null
+++ b/internal/util/router_auth_check.go
@@ -0,0 +1,33 @@
+package util
+
+import (
+	"net/http"
+
+	"github.com/gin-gonic/gin"
+
+	nssf_context "github.com/free5gc/nssf/internal/context"
+	"github.com/free5gc/nssf/internal/logger"
+)
+
+type RouterAuthorizationCheck struct {
+	serviceName string
+}
+
+func NewRouterAuthorizationCheck(serviceName string) *RouterAuthorizationCheck {
+	return &RouterAuthorizationCheck{
+		serviceName: serviceName,
+	}
+}
+
+func (rac *RouterAuthorizationCheck) Check(c *gin.Context, nssfContext nssf_context.NFContext) {
+	token := c.Request.Header.Get("Authorization")
+	err := nssfContext.AuthorizationCheck(token, rac.serviceName)
+	if err != nil {
+		logger.UtilLog.Debugf("RouterAuthorizationCheck: Check Unauthorized: %s", err.Error())
+		c.JSON(http.StatusUnauthorized, gin.H{"error": err.Error()})
+		c.Abort()
+		return
+	}
+
+	logger.UtilLog.Debugf("RouterAuthorizationCheck: Check Authorized")
+}
diff --git a/internal/util/router_auth_check_test.go b/internal/util/router_auth_check_test.go
new file mode 100644
index 0000000..bf4ecf0
--- /dev/null
+++ b/internal/util/router_auth_check_test.go
@@ -0,0 +1,91 @@
+package util
+
+import (
+	"net/http"
+	"net/http/httptest"
+	"testing"
+
+	"github.com/gin-gonic/gin"
+	"github.com/pkg/errors"
+)
+
+const (
+	Valid   = "valid"
+	Invalid = "invalid"
+)
+
+type mockNSSFContext struct{}
+
+func newMockNSSFContext() *mockNSSFContext {
+	return &mockNSSFContext{}
+}
+
+func (m *mockNSSFContext) AuthorizationCheck(token string, serviceName string) error {
+	if token == Valid {
+		return nil
+	}
+
+	return errors.New("invalid token")
+}
+
+func TestRouterAuthorizationCheck_Check(t *testing.T) {
+	// Mock gin.Context
+	w := httptest.NewRecorder()
+	c, _ := gin.CreateTestContext(w)
+
+	var err error
+	c.Request, err = http.NewRequest("GET", "/", nil)
+	if err != nil {
+		t.Errorf("error on http request: %+v", err)
+	}
+
+	type Args struct {
+		token string
+	}
+	type Want struct {
+		statusCode int
+	}
+
+	tests := []struct {
+		name string
+		args Args
+		want Want
+	}{
+		{
+			name: "Valid Token",
+			args: Args{
+				token: Valid,
+			},
+			want: Want{
+				statusCode: http.StatusOK,
+			},
+		},
+		{
+			name: "Invalid Token",
+			args: Args{
+				token: Invalid,
+			},
+			want: Want{
+				statusCode: http.StatusUnauthorized,
+			},
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			w = httptest.NewRecorder()
+			c, _ = gin.CreateTestContext(w)
+			c.Request, err = http.NewRequest("GET", "/", nil)
+			if err != nil {
+				t.Errorf("error on http request: %+v", err)
+			}
+			c.Request.Header.Set("Authorization", tt.args.token)
+
+			rac := NewRouterAuthorizationCheck("testService")
+			rac.Check(c, newMockNSSFContext())
+			if w.Code != tt.want.statusCode {
+				t.Errorf("StatusCode should be %d, but got %d", tt.want.statusCode, w.Code)
+			}
+		})
+	}
+}