diff --git a/api/src/middlewares/verifyAdminIfNeeded.ts b/api/src/middlewares/verifyAdminIfNeeded.ts
index 999edfa..de39eac 100644
--- a/api/src/middlewares/verifyAdminIfNeeded.ts
+++ b/api/src/middlewares/verifyAdminIfNeeded.ts
@@ -8,8 +8,8 @@ export const verifyAdminIfNeeded: RequestHandler = (req, res, next) => {
   if (!user?.isAdmin) {
     let adminAccountRequired: boolean = true
 
-    if (req.params.userId) {
-      adminAccountRequired = user?.userId !== req.params.userId
+    if (req.params.uid) {
+      adminAccountRequired = user?.userId !== req.params.uid
     } else if (req.params.username) {
       adminAccountRequired = user?.username !== req.params.username
     }
diff --git a/api/src/routes/api/group.ts b/api/src/routes/api/group.ts
index 7db3f77..7b2be9c 100644
--- a/api/src/routes/api/group.ts
+++ b/api/src/routes/api/group.ts
@@ -1,7 +1,11 @@
 import express from 'express'
 import { GroupController } from '../../controllers/'
 import { authenticateAccessToken, verifyAdmin } from '../../middlewares'
-import { getGroupValidation, registerGroupValidation } from '../../utils'
+import {
+  getGroupValidation,
+  registerGroupValidation,
+  uidValidation
+} from '../../utils'
 
 const groupRouter = express.Router()
 
@@ -34,7 +38,10 @@ groupRouter.get('/', authenticateAccessToken, async (req, res) => {
 })
 
 groupRouter.get('/:uid', authenticateAccessToken, async (req, res) => {
-  const { uid } = req.params
+  const { error: uidError, value: params } = uidValidation(req.params)
+  if (uidError) return res.status(400).send(uidError.details[0].message)
+
+  const { uid } = params
 
   const controller = new GroupController()
   try {
@@ -76,7 +83,6 @@ groupRouter.post(
       const response = await controller.addUserToGroup(groupUid, userUid)
       res.send(response)
     } catch (err: any) {
-      console.log('err :>> ', err)
       res.status(err.code).send(err.message)
     }
   }
@@ -104,7 +110,10 @@ groupRouter.delete(
   authenticateAccessToken,
   verifyAdmin,
   async (req, res) => {
-    const { uid } = req.params
+    const { error: uidError, value: params } = uidValidation(req.params)
+    if (uidError) return res.status(400).send(uidError.details[0].message)
+
+    const { uid } = params
 
     const controller = new GroupController()
     try {
diff --git a/api/src/routes/api/permission.ts b/api/src/routes/api/permission.ts
index b45af93..c5d5390 100644
--- a/api/src/routes/api/permission.ts
+++ b/api/src/routes/api/permission.ts
@@ -3,6 +3,7 @@ import { PermissionController } from '../../controllers/'
 import { verifyAdmin } from '../../middlewares'
 import {
   registerPermissionValidation,
+  uidValidation,
   updatePermissionValidation
 } from '../../utils'
 
@@ -35,7 +36,10 @@ permissionRouter.post('/', verifyAdmin, async (req, res) => {
 })
 
 permissionRouter.patch('/:uid', verifyAdmin, async (req: any, res) => {
-  const { uid } = req.params
+  const { error: uidError, value: params } = uidValidation(req.params)
+  if (uidError) return res.status(400).send(uidError.details[0].message)
+
+  const { uid } = params
 
   const { error, value: body } = updatePermissionValidation(req.body)
   if (error) return res.status(400).send(error.details[0].message)
@@ -51,8 +55,10 @@ permissionRouter.patch('/:uid', verifyAdmin, async (req: any, res) => {
 })
 
 permissionRouter.delete('/:uid', verifyAdmin, async (req: any, res) => {
-  const { uid } = req.params
+  const { error: uidError, value: params } = uidValidation(req.params)
+  if (uidError) return res.status(400).send(uidError.details[0].message)
 
+  const { uid } = params
   try {
     await controller.deletePermission(uid)
     res.status(200).send('Permission Deleted!')
diff --git a/api/src/routes/api/spec/group.spec.ts b/api/src/routes/api/spec/group.spec.ts
index 72215a2..711c31c 100644
--- a/api/src/routes/api/spec/group.spec.ts
+++ b/api/src/routes/api/spec/group.spec.ts
@@ -11,6 +11,7 @@ import {
 } from '../../../utils'
 import Group, { PUBLIC_GROUP_NAME } from '../../../model/Group'
 import User from '../../../model/User'
+import { randomBytes } from 'crypto'
 
 const clientId = 'someclientID'
 const adminUser = {
@@ -75,7 +76,7 @@ describe('group', () => {
         .send(group)
         .expect(200)
 
-      expect(res.body.groupId).toBeTruthy()
+      expect(res.body.uid).toBeTruthy()
       expect(res.body.name).toEqual(group.name)
       expect(res.body.description).toEqual(group.description)
       expect(res.body.isActive).toEqual(true)
@@ -201,8 +202,10 @@ describe('group', () => {
     })
 
     it('should respond with Not Found if groupId is incorrect', async () => {
+      const hexValue = randomBytes(12).toString('hex')
+
       const res = await request(app)
-        .delete(`/SASjsApi/group/1234`)
+        .delete(`/SASjsApi/group/${hexValue}`)
         .auth(adminAccessToken, { type: 'bearer' })
         .send()
         .expect(404)
@@ -253,7 +256,7 @@ describe('group', () => {
         .send()
         .expect(200)
 
-      expect(res.body.groupId).toBeTruthy()
+      expect(res.body.uid).toBeTruthy()
       expect(res.body.name).toEqual(group.name)
       expect(res.body.description).toEqual(group.description)
       expect(res.body.isActive).toEqual(true)
@@ -274,7 +277,7 @@ describe('group', () => {
         .send()
         .expect(200)
 
-      expect(res.body.groupId).toBeTruthy()
+      expect(res.body.uid).toBeTruthy()
       expect(res.body.name).toEqual(group.name)
       expect(res.body.description).toEqual(group.description)
       expect(res.body.isActive).toEqual(true)
@@ -292,8 +295,10 @@ describe('group', () => {
     })
 
     it('should respond with Not Found if groupId is incorrect', async () => {
+      const hexValue = randomBytes(12).toString('hex')
+
       const res = await request(app)
-        .get('/SASjsApi/group/1234')
+        .get(`/SASjsApi/group/${hexValue}`)
         .auth(adminAccessToken, { type: 'bearer' })
         .send()
         .expect(404)
@@ -312,7 +317,7 @@ describe('group', () => {
           .send()
           .expect(200)
 
-        expect(res.body.groupId).toBeTruthy()
+        expect(res.body.uid).toBeTruthy()
         expect(res.body.name).toEqual(group.name)
         expect(res.body.description).toEqual(group.description)
         expect(res.body.isActive).toEqual(true)
@@ -333,7 +338,7 @@ describe('group', () => {
           .send()
           .expect(200)
 
-        expect(res.body.groupId).toBeTruthy()
+        expect(res.body.uid).toBeTruthy()
         expect(res.body.name).toEqual(group.name)
         expect(res.body.description).toEqual(group.description)
         expect(res.body.isActive).toEqual(true)
@@ -379,7 +384,7 @@ describe('group', () => {
 
       expect(res.body).toEqual([
         {
-          groupId: expect.anything(),
+          uid: expect.anything(),
           name: group.name,
           description: group.description
         }
@@ -401,7 +406,7 @@ describe('group', () => {
 
       expect(res.body).toEqual([
         {
-          groupId: expect.anything(),
+          uid: expect.anything(),
           name: group.name,
           description: group.description
         }
@@ -431,13 +436,13 @@ describe('group', () => {
         .send()
         .expect(200)
 
-      expect(res.body.groupId).toBeTruthy()
+      expect(res.body.uid).toBeTruthy()
       expect(res.body.name).toEqual(group.name)
       expect(res.body.description).toEqual(group.description)
       expect(res.body.isActive).toEqual(true)
       expect(res.body.users).toEqual([
         {
-          id: expect.anything(),
+          uid: expect.anything(),
           username: user.username,
           displayName: user.displayName
         }
@@ -465,7 +470,7 @@ describe('group', () => {
 
       expect(res.body.groups).toEqual([
         {
-          groupId: expect.anything(),
+          uid: expect.anything(),
           name: group.name,
           description: group.description
         }
@@ -486,13 +491,13 @@ describe('group', () => {
         .send()
         .expect(200)
 
-      expect(res.body.groupId).toBeTruthy()
+      expect(res.body.uid).toBeTruthy()
       expect(res.body.name).toEqual(group.name)
       expect(res.body.description).toEqual(group.description)
       expect(res.body.isActive).toEqual(true)
       expect(res.body.users).toEqual([
         {
-          id: expect.anything(),
+          uid: expect.anything(),
           username: 'addUserRandomUser',
           displayName: user.displayName
         }
@@ -526,8 +531,10 @@ describe('group', () => {
     })
 
     it('should respond with Not Found if groupId is incorrect', async () => {
+      const hexValue = randomBytes(12).toString('hex')
+
       const res = await request(app)
-        .post('/SASjsApi/group/123/123')
+        .post(`/SASjsApi/group/${hexValue}/123`)
         .auth(adminAccessToken, { type: 'bearer' })
         .send()
         .expect(404)
@@ -538,8 +545,10 @@ describe('group', () => {
 
     it('should respond with Not Found if userId is incorrect', async () => {
       const dbGroup = await groupController.createGroup(group)
+      const hexValue = randomBytes(12).toString('hex')
+
       const res = await request(app)
-        .post(`/SASjsApi/group/${dbGroup.uid}/123`)
+        .post(`/SASjsApi/group/${dbGroup.uid}/${hexValue}`)
         .auth(adminAccessToken, { type: 'bearer' })
         .send()
         .expect(404)
@@ -626,7 +635,7 @@ describe('group', () => {
         .send()
         .expect(200)
 
-      expect(res.body.groupId).toBeTruthy()
+      expect(res.body.uid).toBeTruthy()
       expect(res.body.name).toEqual(group.name)
       expect(res.body.description).toEqual(group.description)
       expect(res.body.isActive).toEqual(true)
@@ -723,8 +732,10 @@ describe('group', () => {
     })
 
     it('should respond with Not Found if groupId is incorrect', async () => {
+      const hexValue = randomBytes(12).toString('hex')
+
       const res = await request(app)
-        .delete('/SASjsApi/group/123/123')
+        .delete(`/SASjsApi/group/${hexValue}/123`)
         .auth(adminAccessToken, { type: 'bearer' })
         .send()
         .expect(404)
@@ -735,8 +746,10 @@ describe('group', () => {
 
     it('should respond with Not Found if userId is incorrect', async () => {
       const dbGroup = await groupController.createGroup(group)
+      const hexValue = randomBytes(12).toString('hex')
+
       const res = await request(app)
-        .delete(`/SASjsApi/group/${dbGroup.uid}/123`)
+        .delete(`/SASjsApi/group/${dbGroup.uid}/${hexValue}`)
         .auth(adminAccessToken, { type: 'bearer' })
         .send()
         .expect(404)
diff --git a/api/src/routes/api/spec/permission.spec.ts b/api/src/routes/api/spec/permission.spec.ts
index b8580ff..ccdd120 100644
--- a/api/src/routes/api/spec/permission.spec.ts
+++ b/api/src/routes/api/spec/permission.spec.ts
@@ -17,6 +17,7 @@ import {
   PermissionDetailsResponse
 } from '../../../controllers'
 import { generateAccessToken, saveTokensInDB } from '../../../utils'
+import { randomBytes } from 'crypto'
 
 const deployPayload = {
   appLoc: 'string',
@@ -281,17 +282,19 @@ describe('permission', () => {
       expect(res.body).toEqual({})
     })
 
-    it('should respond with Bad Request if principalId is not a number', async () => {
+    it('should respond with Bad Request if principalId is not a string of 24 hex characters', async () => {
       const res = await request(app)
         .post('/SASjsApi/permission')
         .auth(adminAccessToken, { type: 'bearer' })
         .send({
           ...permission,
-          principalId: 'someCharacters'
+          principalId: randomBytes(10).toString('hex')
         })
         .expect(400)
 
-      expect(res.text).toEqual('"principalId" must be a number')
+      expect(res.text).toEqual(
+        '"principalId" length must be 24 characters long'
+      )
       expect(res.body).toEqual({})
     })
 
@@ -321,7 +324,7 @@ describe('permission', () => {
         .auth(adminAccessToken, { type: 'bearer' })
         .send({
           ...permission,
-          principalId: 123
+          principalId: randomBytes(12).toString('hex')
         })
         .expect(404)
 
@@ -336,7 +339,7 @@ describe('permission', () => {
         .send({
           ...permission,
           principalType: 'group',
-          principalId: 123
+          principalId: randomBytes(12).toString('hex')
         })
         .expect(404)
 
@@ -437,8 +440,9 @@ describe('permission', () => {
     })
 
     it('should respond with not found (404) if permission with provided id does not exist', async () => {
+      const hexValue = randomBytes(12).toString('hex')
       const res = await request(app)
-        .patch('/SASjsApi/permission/123')
+        .patch(`/SASjsApi/permission/${hexValue}`)
         .auth(adminAccessToken, { type: 'bearer' })
         .send({
           setting: PermissionSettingForRoute.deny
@@ -466,8 +470,10 @@ describe('permission', () => {
     })
 
     it('should respond with not found (404) if permission with provided id does not exists', async () => {
+      const hexValue = randomBytes(12).toString('hex')
+
       const res = await request(app)
-        .delete('/SASjsApi/permission/123')
+        .delete(`/SASjsApi/permission/${hexValue}`)
         .auth(adminAccessToken, { type: 'bearer' })
         .send()
         .expect(404)
diff --git a/api/src/routes/api/spec/user.spec.ts b/api/src/routes/api/spec/user.spec.ts
index 734dc5b..71ceb88 100644
--- a/api/src/routes/api/spec/user.spec.ts
+++ b/api/src/routes/api/spec/user.spec.ts
@@ -1,3 +1,4 @@
+import { randomBytes } from 'crypto'
 import { Express } from 'express'
 import mongoose, { Mongoose } from 'mongoose'
 import { MongoMemoryServer } from 'mongodb-memory-server'
@@ -690,8 +691,10 @@ describe('user', () => {
     it('should respond with Not Found if userId is incorrect', async () => {
       await controller.createUser(user)
 
+      const hexValue = randomBytes(12).toString('hex')
+
       const res = await request(app)
-        .get('/SASjsApi/user/1234')
+        .get(`/SASjsApi/user/${hexValue}`)
         .auth(adminAccessToken, { type: 'bearer' })
         .send()
         .expect(404)
@@ -803,13 +806,13 @@ describe('user', () => {
 
       expect(res.body).toEqual([
         {
-          id: expect.anything(),
+          uid: expect.anything(),
           username: adminUser.username,
           displayName: adminUser.displayName,
           isAdmin: adminUser.isAdmin
         },
         {
-          id: expect.anything(),
+          uid: expect.anything(),
           username: user.username,
           displayName: user.displayName,
           isAdmin: user.isAdmin
@@ -831,13 +834,13 @@ describe('user', () => {
 
       expect(res.body).toEqual([
         {
-          id: expect.anything(),
+          uid: expect.anything(),
           username: adminUser.username,
           displayName: adminUser.displayName,
           isAdmin: adminUser.isAdmin
         },
         {
-          id: expect.anything(),
+          uid: expect.anything(),
           username: 'randomUser',
           displayName: user.displayName,
           isAdmin: user.isAdmin
diff --git a/api/src/routes/api/spec/web.spec.ts b/api/src/routes/api/spec/web.spec.ts
index f5529aa..06aa7f1 100644
--- a/api/src/routes/api/spec/web.spec.ts
+++ b/api/src/routes/api/spec/web.spec.ts
@@ -145,7 +145,7 @@ describe('web', () => {
 
       expect(res.body.loggedIn).toBeTruthy()
       expect(res.body.user).toEqual({
-        id: expect.any(Number),
+        id: expect.anything(),
         username: user.username,
         displayName: user.displayName,
         isAdmin: user.isAdmin,
diff --git a/api/src/routes/api/user.ts b/api/src/routes/api/user.ts
index 2dcaf14..987e027 100644
--- a/api/src/routes/api/user.ts
+++ b/api/src/routes/api/user.ts
@@ -9,6 +9,7 @@ import {
   deleteUserValidation,
   getUserValidation,
   registerUserValidation,
+  uidValidation,
   updateUserValidation
 } from '../../utils'
 
@@ -57,7 +58,10 @@ userRouter.get(
 )
 
 userRouter.get('/:uid', authenticateAccessToken, async (req, res) => {
-  const { uid } = req.params
+  const { error, value: params } = uidValidation(req.params)
+  if (error) return res.status(400).send(error.details[0].message)
+
+  const { uid } = params
 
   const controller = new UserController()
   try {
@@ -102,7 +106,11 @@ userRouter.patch(
   verifyAdminIfNeeded,
   async (req, res) => {
     const { user } = req
-    const { uid } = req.params
+
+    const { error: uidError, value: params } = uidValidation(req.params)
+    if (uidError) return res.status(400).send(uidError.details[0].message)
+
+    const { uid } = params
 
     // only an admin can update `isActive` and `isAdmin` fields
     const { error, value: body } = updateUserValidation(req.body, user!.isAdmin)
@@ -152,7 +160,11 @@ userRouter.delete(
   verifyAdminIfNeeded,
   async (req, res) => {
     const { user } = req
-    const { uid } = req.params
+
+    const { error: uidError, value: params } = uidValidation(req.params)
+    if (uidError) return res.status(400).send(uidError.details[0].message)
+
+    const { uid } = params
 
     // only an admin can delete user without providing password
     const { error, value: data } = deleteUserValidation(req.body, user!.isAdmin)
diff --git a/api/src/utils/validation.ts b/api/src/utils/validation.ts
index 10d456e..11f2634 100644
--- a/api/src/utils/validation.ts
+++ b/api/src/utils/validation.ts
@@ -12,6 +12,11 @@ const groupnameSchema = Joi.string().lowercase().alphanum().min(3).max(16)
 
 export const blockFileRegex = /\.(exe|sh|htaccess)$/i
 
+export const uidValidation = (data: any) =>
+  Joi.object({
+    uid: Joi.string().length(24).hex().required()
+  }).validate(data)
+
 export const getUserValidation = (data: any): Joi.ValidationResult =>
   Joi.object({
     username: usernameSchema.required()
@@ -113,7 +118,7 @@ export const registerPermissionValidation = (data: any): Joi.ValidationResult =>
     principalType: Joi.string()
       .required()
       .valid(...Object.values(PrincipalType)),
-    principalId: Joi.string().required()
+    principalId: Joi.string().length(24).hex().required()
   }).validate(data)
 
 export const updatePermissionValidation = (data: any): Joi.ValidationResult =>