Rajashekar KankanalaRajashekarKankanalaTuts RajaNTR ColonyHyderabad, Telangana,500087India9110760272//www.tutsraja.com/

21 July, 2019

Firefox Addons for Hacking

Top 6 Firefox AddOns for Hacking

We have seen several types of web application attacks. In almost all the cases, we are using browsers. Now I want to show you a little advancement on our browsers which can be used for different types of attacks and testing.

We have some beautiful Firefox add-ons every hacking aspirant should know about. Here I will give detailed explanation and functionality of few add-ons.

Firefox addons:

  1. Hack bar
  2. Advanced cookie manager
  3. Tamper Data
  4. Fire Bug
  5. SQL inject me
  6. Live http headers

1. Hack bar:

You needed to spend couple of needless minutes for counting. It will display all the columns in our union statement automatically. This is just an example of what we can do with hack bar. It has many wonderful features like MD5, SHA1 encryption, encoding the data etc.

Here I am showing some screen shots of sample usage of hack bar.

First install hack bar add on to your Mozilla Firefox browser.

Then, open it by doing the following.You can go to tools a show/hide hack bar.

Now after launching our hack bar, I am going to create an MD5 hash for the text admin.

Hack_bar_user_interface

After following the above shown steps, I got my 32-bit MD5 hash for the text admin (Look below picture).

Hack_bar_addon_output

2. Advanced Cookie Manager:

It is a nice add-on with which we can edit and add sessions. This tool allows us to grab the cookies of one session and to add them to another session, if we want.

This is a nice tool to use the cookies stolen in an XSS attack.

Here I am showing a screenshot of how we can edit the cookies.

Open the advanced cookie manager add-on by doing the following.

Now select the website you want to set the cookie. Select the cookie name and replace.

Advanced_cookie_manager_user_interface

3. Tamper Data:

Tamper data is one more beautiful add on which allows us to view, modify the HTTP requests and parameters. Using tamper data we can change the online game scores.

Earlier, I used this add-on for sms spoofing on a well known free sms website. (Now it is fixed).

As we did with our previous add-ons we need to install it first.

I will first start tamper data add-on by doing the following. Firefox->tools->tamper data

It opens a new browser window, when you click on start tamper. We can take it as a reference and use it on any website you want. It looks like the following.

Tamper_Data_on_going_reports


Gmail_login_for_tamper_data

In my case, I have used example below. Our add-on opens a new window as shown below.

Well, what should I do now?

Tamper_with_request

As I want to view and modify the data, I will click 'tamper' button.

It opens all the intercepted data which we can modify and then submit it to the server.

In precise, before submitting the data to the server from the browser, we are intercepting and modifying the data. This is very useful in hacking game scores, uploading shells etc.

4. Fire Bug:

In many cases, when we browse websites and enter details into forms, we may find some annoying message boxes saying please enter correct details.

If it is because of client side validation using JavaScript, then we can bypass that validation very easily using fire bug.

Fire bug is a nice add-on for modifying the content of the page (HTML and JavaScript). We can easily modify the source.

Try if website having client side validation. To open firebug, just press F12. Now, you can see the following figure to understand, how I bypass the JavaScript validation using fire bug.

Fire_Bug_Godaddy_interface

In the above figure, we have onclick=”validate()” for validation when we click purchase button. So just by removing that line we can bypass the validation.

5. SQL inject me:

This is also a nice tool, which can be used to test for SQL injection vulnerabilities on web applications. It reduces the manual efforts by automating the testing process. This tool automatically submits the forms by substituting the form values with SQL strings.

Just select the form where you need to check for SQL injection and in the browser tools SQL inject me àopen SQL inject me slide bar.

6. Live http headers:

Live http headers is one more beautiful add-on we need to know about. This is also similar to tamper data. We can view all the headers of http requests and even responses.

We can also modify the content before submitting it to the server. It can be used to upload shells when extension is blocked by the administrator of the website.

Live_http_headers_interface

Credit: Sai Satish (Indian Servers CEO)

18 July, 2019

Keyloggers for Windows

How to Fool Keyloggers

What is Keylogger:

You might have heard about a dangerous application called Keylogger. It's a very tricky tool to record your keystrokes in a notepad file. Whenever you type anything using keyboard, this software stores all your keystrokes.

These days everybody is more interested in spying on someone, in college, at work, in the home.

If you access the Internet from any cyber cafe or any public PC, this post is a must for you. Keylogger is many hackers and script kiddies’ favorite tool.

Types of Keyloggers:

  1. Software keyloggers
  2. Hardware keyloggers

1. Software Keyloggers:

The software keylogger is small software, you need to install that software on victim computers. It is software, which records each and every keystroke you enter, including mouse clicks.

Software keylogger can be installed in the victim’s system even if they use security updated. Which make a keylogger undetectable by latest antivirus? .There are many keyloggers available in the market with various features. Let's See.

1. Ardamax keylogger

Ardamax keylogger

  • Capture chats
  • Visual surveillance
  • Advanced security
  • Remain invisible
  • Monitor remotely
  • Use the microphone to record audio
  • I suggest you to Download and Install.
Other Alternatives:
  1. Perfect keylogger
  2. Invisible keylogger
  3. Win-spy
  4. Free Keylogger
  5. Revealer Keylogger Free
  6. DanuSoft Free Keylogger
  7. Real Free Keylogger
  8. KidLogger http://kidlogger.net/download.html
  9. Actual Keylogger
  10. BlackBox Express
  11. G3 ISam
  12. Spyrix Free Keylogger
  13. Ardamax Keylogger
  14. Myjad Keylogger
  15. Simple Python Keylogger
  16. Any Keylogger
  17. Ultimate Keylogger

2. Hardware Keyloggers:

Hardware keyloggers are also available, which will be inserted between keyboard and CPU. This is a thumb-sized device. It records all the keystrokes you enter from the keyboard then saves it, in its memory. Later this data will be analyzed.

The drawback of this device is, it can’t record mouse clicks, can’t take screenshots.

Hardly has it taken a minute to install this software/hardware in victim’s system, from next second onwards attacker will get every activity going on in victim’s computer.

What they are chatting, which sites they are browsing, victim usernames, passwords what’s not? Each and every activity happening in victims system with screenshots will be recorded.

This activity will be saved in victims system or it can be mailed how attackers do this along with protection techniques.

1. USB Key logger

USB Key logger

  • Huge memory capacity (up to 8 gigabytes)
  • Strong 128-bit encryption
  • Super fast memory contents download
  • Works with any USB keyboard
  • Undetectable for security scanners
  • Quick and easy national layout support
  • Transparent to computer operation
  • Ultra compact and discreet
  • I suggest you to Download and Install.
Other Alternatives
  1. Keyllama Keylogger.
  2. SerialGhost
  3. Airdrive Keylogger Pro

Tricks to Fool Keyloggers:

Yes, it is possible to fool a keylogger.

Just think, You went outside you must access a public computer and you don’t have other choices – feeling afraid. Don’t worry there are many ways of fooling keyloggers. It is a little tricky and somewhat difficult but surely worthy.

1. Use Virtual Keyboard, whenever you access PC from any cyber cafe. Use Virtual Keyboard or On-Screen Keyboard for entering the password.

How to enable virtual keyboard: Press windows button and type OSK.

Just use mouse clicks for entering password and username. By using the on-screen keyboard, the keylogger will never detect your keystrokes, thus your account will be safe.

2. Use Anti Keylogger software. If you do not know whether keylogger is installed or not. You can use software called Elite Anti Keylogger. It has more than 1000 known keyloggers and will warn you immediately. It will detect any keylogger.

3. If you want to type a password, never type the complete password directly. Additionally, you can also use spaces with your passwords as spaces are not readable. Use 2-3 spaces after or in the end for all your passwords.

We should confuse keylogger by giving keys which are not there in our password and removing them by using keys like delete, page down, page up, up, down, left, right keys.

Key logger’s job is to record all the keystrokes we enter. This is what we studied earlier. So, to fool a keylogger, enter unnecessary keys along with the password.

Still confused? Let’s see the example,

Example to Fool Keylogger :

Ex: if my password is 123456, then keylogger will record 123456 as it is, whenever I enter in the password box. To fool a keylogger, I will type in password dk21e3294H15h06 (left arrow & 2 times backspace in sequence for 5 times) then final output is 123456 which is required text.

Don’t go to the internet café without any preparation. If you want to access you’re your mail, social networking sites or bank accounts, you must fool keyloggers. Whenever you need to type a password, never type the complete password directly. If it is hardware keylogger use online screen keyboard. To open this go to Run and type OSK.

Note: If you want to be safe side don’t use unknown computers. Recommended tip is to use your own computer.

There are many keyloggers that are not detected by antivirus and other security applications.

Take Precautions.

  • Bring your own Computer!
  • Check for Hardware Keyloggers
  • Use a USB Stick to secure your Personal Data
  • Use Anti-Keylogger or KeyScrambler Programs on your USB drive
  • Subscribe for OTP – One Time Passwords for Online Banking
  • Use Mail forwarding for simply checking your Yahoo or Gmail

Credit: Sai Satish (Indian Servers CEO)

16 July, 2019

List of National Awards in India

List of National Awards

An award is a prize or certificate that a person is given for doing something well in any field. Awards are different types, depends on the field of work.

The award was given for outstanding contribution towards in the field of arts, literature, science and public service. Padma awards are given exceptional and distinguished service in any field.

Bharat Ratna is the highest civilian award in India. Gallantry awards are given for the brave and gallant people etc.

List of National Awards

S.NoAwardField of Contribution
1.Bharat RatnaArts, Literature, Science and Public Services
Padma Awards
2.Padma VibhushanExceptional and distinguished service.
3.Padma BhushanDistinguished service of a high order.
4.Padma ShriExceptional and distinguished service in any field.
Gallantry Awards
5.Param Vir Chakra (PVC)Distinguished acts of valour during wartime.
6.Ashok ChakraValour, courageous action or self-sacrifice away from the battlefield.
7.Shaurya ChakraValour, courageous action or self-sacrifice while not engaged in direct action with the enemy.
Important Indian Awards
8.Nobel PrizeLiterature, Medicine, Physics, Chemistry, Peace, and Economics
9.Karbir SammanSocio Communal Harmony
10.Saraswati SammanPoetry literary works in any 22 Indian language listed in Schedule VIII of the Constitution of India
11.Sangeet-Natak Akademi AwardMusic, dance and Drama
12.Vachaspati SammanSanskrit Literature
13.Vyas SammanLiterature
14.Moorti Devi Award
15.Jnanpith award
16Bihari Puraskar
17.Dadasaheb Phalke AwardCinema/Films
18.Dhyan Chand Awardveteran sports persons
19.Rajiv Gandhi Khel Ratna Awardsports person
20Arjuna Award
21Dronacharya AwardEminent coaches
22Shanti Swarup Bhatnagar PrizeScience & Technology
23Dhanwantari AwardMedical Science
24International Gandhi Peace PrizeSocial, Economic and Political revolution
25Lal Bahadur Shastri National AwardPublic Administration, Academics and Management
26Sahitya Akademi AwardBooks in Indian Languages and English.
Other Awards
1BAFTA AwardsTelevision, Films, Video Games and Animation
2Bourlog AwardAgriculture
3Pritzker PrizeArchitecture
4The Oscar/Academy AwardsFilms
5Booker PrizeLiterature
6Stirling PrizeArchitecture
7Aga Khan Award
8Kalinga PrizeScience
9Grammy AwardMusic
10Abel PrizeMathematics
11Green Star AwardsEnvironmental disasters
12Magsaysay AwardPublic Service, Leadership, Journalism, Literature,creative arts and international understanding.
13Pulitzer PrizeNewspaper and Online journalism, Literature, and Musical composition
14Manthan AwardE-Content and Creativity
15FiFi AwardsIndustry’s creative achievements

Check Your Score

Rajashekar KankanalaRajashekarKankanala
Tuts Raja
NTR Colony
Hyderabad,Telangana,500087India
9110760272
http://www.tutsraja.com/

14 July, 2019

Best Free Password Manager

Password Manager

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Introduction to the Password Manager:

The password managers are used to store passwords in the encrypted format and provide secure access to the user with the help of a master password. It helps to protect consumers from identity theft.

A free password manager is an excellent way to avoid forgetting the password to your email account, Windows login, an Excel document, other files on the system, or whatever service you use passwords to access.

Once you unlock your password manager with the master password, you can have access to the other passwords that you have saved inside your account.

Password managers are becoming more and more popular. You can also use these to set more complex, less vulnerable passwords without the need to remember all of them. The list of keeping these passwords is endless.

A password manager is simple. The password manager can store passwords in the encrypted vault. You can access them quickly with any device.

Password managers not only store login information but also store billing address, credit cards, and social security information.

What Makes a Free Password Manager the Best?

There are many free password managers but not all the best. The first concern is security and trust. You’re storing all your personal data in a password manager, so you need to know it can’t access your account data.

Sharing capabilities, browser import, and a security dashboard is not important. They don’t significantly affect the core functions of the password manager.

Why You Need a Password Manager ?

A password manager makes the internet on your desktop and mobiles devices easier and more secure than ever. It is impossible to remember different passwords of your accounts.

The password managers capture your credentials during account creation. When you change password online, it will ask to update the password for the site.

The password capture only works if the password manager recognizes that you're logging in to a secure site. So non-standard login pages are can cause trouble.

When you revisit a site for which you have saved credentials will automatically fill from saved data. A password manager could be very helpful in today’s time. People use their fingerprint, face, eyes, etc. to authenticate password word managers.

Use of a password manager:

A password manager can remember your credentials by storing them in an encrypted form and provide the details whenever required. It is better instead of writing password credentials in a notebook.

A password manager can generate strong passwords with a combination of letters, numbers and special characters, and store them all in an encrypted vault. Nowadays, many password managers offer cross-platform support.

Top Password Managers:

Every password manager has its own set of pros and cons. choosing a password manager depends on user interests and requirements.

1. Last Pass:

lastpass

The LastPass has many features including auto-filling a password into apps, sites, and forms. It also allows you to store photos and audio notes securely.

It has unique features such as fingerprint scanner support, a password generator, and a password auditor, emergency access to a friend or family member.

Now stop wasting time writing, remembering, and resetting passwords. Remember only one master password for all your accounts. You can focus on the important things in life instead of remembering.

LastPass uses AES 256 bit to encrypt your vault. Encryption and decryption happen locally, that means service cannot see the information in your account. Master password and decryption key are secure never sent to the servers, only password hash is sent to the server.

It will refuse to auto-complete forms on known phishing websites. You can export your data at any time if you decide to switch another password manager. It can also import data from other popular web browsers.

Last Pass extensions are available all standard web browsers. Independent software is also available for the Windows operating system. It is browser-based password manager that runs on Chrome, Firefox or Internet Explorer.

Pros:
  • Multi-device sync.
  • Excellent security.
  • Stores unlimited logins.
  • Automatic form completion.
  • Generates strong passwords.
  • One-to-many sharing.
  • Emergency access.
  • Two-factor authentication.
  • Automatic password capture.
  • Syncs passwords across Windows, macOS, Android, and iOS devices.
Cons:
  • Limited sharing capabilities.
  • No new interface in Opera and Internet Explorer.
  • Some components out of date.

2. KeePass :

keepass

KeePass is a free open source password manager. Anyone can inspect the code for potential weaknesses and security issues. Anyone can be identified and fixed quickly. You can put all your passwords in one database and locked with one master key or a key file.

You have to remember only one master password or key file to unlock the whole database. The databases are encrypted by secure encryption algorithms currently known as AES and Twofis. Both encryption algorithms are very secure.

KeePass is portable no installation is required and can be carried on a USB stick without any installation. it is a well-known Windows desktop password manager but it’s also available for macOS and Linux. It has limited features compared to other password managers.

KeePass supports import and export of credentials in many forms XML, HTML, CSV, etc. Password manager supports some common features such as form autofill, two factors authentication, etc. It also includes a built-in password generator tool. It is completely free.

Pros:
  • Handles passwords for any website or application.
  • Two-factor authentication.
  • Imports from many competitors.
  • More than100 plug-ins add features.
  • Includes keylogger-foiling features.
  • A customizable password manager for more experienced users.
  • Excellent password generator.
  • Combination of key file and master password.
  • No installation required.
  • Plugins to extend functionalities.
Cons:
  • Lacks automatic password capture.
  • Password replay launched manually.
  • Synchronizing among devices is complicated.
  • No mobile support.

3. Enpass :

enpass

Enpass is a powerful password manager. It is free and also available desktop versions for Mac, PC, and Linux.

It has feature backup and restores info of you. It has features 256 bit AES encryption, cross-platform and syncing. You can make import and export for device migration. You can also have auto-fill your passwords.

It is free for basic features and you can upgrade with some payment. Enpass makes an easy life by securing and managing your important information and passwords. Cross-platform password management software best fit for every pocket.

It supports different platforms including Windows, macOS, Linux, iOS, Android, Chrome OS, etc. Organize passwords of personal, work, and family.

Pros:
  • Syncs across many platforms.
  • Secure sharing.
  • Automatic password capture.
  • Generates strong passwords.
  • Uses SQLCipher 256-bit AES encryption engine.
  • Time-based one-time passwords.
  • Passwords are not stored on Enpass servers.
Cons:
  • Password replay not fully automated.
  • Offers an insecure sharing option.
  • Not free for mobile use.
  • Didn't capture some common sites.
  • Syncing requires third-party cloud storage.

4. Encryptr :

encryptr

SpiderOak encryptr is a free password manager. It is private and secure password management tool. E-wallet is accessible only by you. Cloud and server of encryptr have zero knowledge of your password information.

No need to remember passwords now. It gives peace for your mind by storing passwords on encryptr. All your data is saved in encrypted format on the cloud. You are the only owner of your keys and passwords. You only see passwords with decrypter.

It makes easy for finding stored passwords, credit card numbers, and notes by using the quick search bar.

Pros:
  • Create and Protect.
  • Need a specific type of password.
  • Password generator.
  • Store and Search.
  • synced for easy access.
  • Secure and Private.
Cons:
  • zero protection for insider attacks.
  • Single key for all;
  • anyone or any application that needs to write, edit, read data will need keys.
  • Many major breaches achieved with TDE turned on.

5. Roboform :

Roboform

RoboForm Free has a lot of features. It has emergency access. So someone close can get to your data in the event of death. It is not an account recovery outside of emergency access.

RoboForm never sees or stores your master password. So you can’t reset it even if you need it to. It is one of the risks of using a password manager but it provides a lot of security.

The free version of RoboForm allows users to store unlimited passwords, automatically fill web forms, single-click logins. Paid versions provide some extra benefits such as cloud sync.

The free plan is decent but it’s missing a few features. The paid version of the software is excellent. You will miss in free plan is multi-device sync and cloud backup, and 2FA security. To get 24/7 support and web access, application logins, secure storage of notes, multi-platform support, and the ability to gain emergency access.

It is available for various platforms such as windows, mac, IOS, and Android. It is a good option for persons who want to sync passwords between laptop, desktop, and mobile platforms. Roboform automatically calculates the strength of the password.

Pros:
  • Unlimited entries.
  • Application auto-fill.
  • Easy to use.
  • Cross-platform.
  • Stores unlimited logins.
  • Stores notes.
  • Auto capturing of the password.
  • Folders for managing passwords easily.
  • Offline access to passwords.
  • Strong search functionality to search passwords.
Cons:
  • No multi-device sync.

6. Dashlane :

Dashlane

Dashlane is a fairly popular password manager app. The free version includes auto-fill, security alerts, storage for up to 50 passwords, and usability on a single device and you won’t be able to sync data between them. It’s not just a Windows desktop program. It is available for Windows, macOS, iOS, Android operating systems.

Dashlane is first picking for paid password managers, not only excellent security and ease of use but also for its many features. It’s costly to upgrade. The dark web monitoring and a single point virtual private network, justify the cost.

You can change passwords from the security dashboard. The free plan is decent. If it wasn’t for the password changer and excellent user experience, though, it’d be difficult to recommend with only 50 entries and no multi-device sync.

Superb password security is for all web browsers and devices. It has featuring one-click password generation, world-class security, breathless ease of use and ability to store notes for future reference.

Dashlane protects AES-256 bit encryption and stores them locally. It supports filling forms, automatic logins, two-factor authentication, import/export of credentials, etc. It will store credit cards, debit cards, and other payment details.

It stores unlimited passwords for you, but it’s only limited to one device. If you go premium option it extends the device limit to unlimited, enables cross-device syncing and cloud backup.

Pros:
  • Easy to use.
  • Breach notifications.
  • Password changer.
  • Strong password generator tool.
  • Store notes, bank information, and credit card details.
  • Share passwords without reveling.
Cons:
  • Limited to 50 entries
  • No multi-device sync

7. TrueKey :

TrueKey

TrueKey is a famous password manager for Windows, macOS, iOS, and Android. It supports web browsers including Chrome, Firefox, and Edge.

TrueKey can be a great password vault app because of its simplicity and various sign-in methods including facial recognition, fingerprint recognition, Windows Hello, two-step verification, etc.

The master password is used to secure passwords and manager login credentials. The free version of the true key allows users to save 15 passwords. It makes some users unhappy.

Login credentials are encrypted and stored locally and synced across all devices on which password manager is used.

Pros:
  • Owned and operated by McAfee.
  • Multiple authentication options.
  • Import passwords from other password managers.
Cons:
  • Poor website design.
  • Only one subscription plan.
  • Cannot be used with Windows phone.

8. LogMeOnce

LogMeOnce

Logmeonce password manager gives more benefits even it is the free version. It is good compared to many other password manager apps.

Features of logmeonce are two-factor authentication options, password strength report, device sync, biometrics support, secure password sharing, digital wallet, etc. It will automatically change weak passwords analyzing in the password strength reports.

The free version of this password manager allows beneficiary. It will receive the control of the account if anything happens to the user.

Pros:
  • Syncs across Windows, macOS, Linux, iOS, and Android.
  • Many options for authentication.
  • Fills credit card data.
  • New, streamlined interface.
  • The vast number of features, many of them unique.
  • Password-less access using PhotoLogin and Fingerprint.
  • 2FA token.
  • Secure Wallet for storing credit card information.
  • Emergency access with photos.
  • Wiping off data stored on the stolen device.
  • Automatic password changer.
Cons:
  • SMS-based two-factor authentication costs money.
  • The vast number of features may overwhelm users.
  • Displays advertisements.

9. Symantec Norton Identity Safe :

Norton Identity Safe

Norton identity safe is a free password manager. It makes logging into your favorite sites easier and more secure via iPhone and google android smartphone.

Norton Identify Safe has all the quality of a basic password manager app. No paid version for Norton identity safe password manager tool. So there is no cutting of features or benefits.

The password manager can easily store password credentials. It provides just one-click logins, auto fills for web forms. The free password manager has the feature to generate strong passwords but available separately.

Norton identity safe supports import/export of login credentials. The Import from other password managers is limited to .csv file format. It is easy to password management software with synchronization between desktop, smartphone, and web browser.

Pros:
  • Synchronization of passwords across all your devices.
  • Norton Safe Web rates website safety.
  • Actionable password strength report.
  • It will alert malicious web pages.
  • Complex password generator.
  • Automatic password changer.
  • Stop filling in the same forms over and over.
Cons:
  • It does not handle address data of form filling.
  • Synchronization is available limited devices.
  • No macOS support.
  • No two-factor authentication.
  • No secure password sharing.

10. Padlock :

Padlock

The padlock is the best password manager. It is a clean interface and open-source code. Open source projects can be easily audited by external entities.

The padlock password manager is simple and secure. It allows you to keep all your passwords under lock and key on your hard drive in a file encrypted with 128-bit encryption. You only access passwords with the master password that you created.

The encryption algorithm used is the AES written by Microsoft Corporation. After entering your master password to access your passwords, it will be automatically logged off in a few minutes.

After you log in to the software with the master password, it will not show your passwords on the screen. You can drag and drop the passwords into most of the apps. No one will see your passwords it is secure.

It will not send any of your information over the web. All data is yours and stored on your computer only.

Pros:
  • The padlock is free to use.
Cons:
  • Sync password to other device is not free.
  • Padlock only implements multi-factor authentication via email.
  • Synchronization authentication is required.
  • Hardware-based tokens.
  • supporting is with OTP.

Tips and Tricks for the Password:

Weak passwords can be decrypted with dictionary attack in a matter of seconds even it has top level AES 256 bit encryption.

To stay safe you need to create best passwords from random letters, special characters, and numbers that cannot be cracked by a dictionary attack.

Other Alternatives:

  1. LessPass
  2. BitWarden
  3. Sticky Password
  4. Myki Password Manager & Authenticator
  5. 1U Password Manager
  6. Avira Password Manager
  7. oneID
  8. Zoho Vault
  9. Abine Blur
  10. Google Password Manager
  11. Kaspersky Password Manager
  12. Keeper
  13. Passopolis (Shutting Down)
  14. 1Password
  15. Ewallet password manager
  16. Bitwarden password manager

Last Updated: 04 April 2019

12 July, 2019

Classification of Numbers

Classification of Numbers

An arithmetical number can express by a word, symbol, or figure. Those are representing a particular quantity and used in counting, measuring and making calculations.

We covered almost all number classifications for Competitive exam point of view. These number classifications are necessary to learn for numerical aptitude.

Decimal Number:

Decimal number contains decimal point. Decimal point is .

Example: 27.45

Digit:

Classification of number system 0, 1, 2,3,4,5,6,7,8 and 9 symbols are called digits.

Example:0,1,2,3,4,5,6,7,8,9.

Number:

Group of digits is called as a number.

Example: 21, 456, 1244, 25734 etc

Face Value:

Face value is nothing but actual value of the digit.

Example: 458
Face value of 4 is 4
Face value of 5 is 5
Face value of 8 is 8

Place Value:

When the value contains digits that is number, such digits counting is units, tens, hundreds, thousands…etc

Example: 342
The place of 2 is units. Place value of 2 * 1 = 2
The place of 4 is tens. Place value of 4 * 10 = 40
The place of 3 is Hundreds. Place value of 3 * 100 = 300

Natural Numbers (N):

Counting numbers without zero is called natural numbers. Natural numbers does not contain zero. Natural numbers denoted by N

Formula: n > 0

Example: 1,2,3,4,5,6,7,8,9,10,11,12…

Whole Numbers (W):

Counting numbers with zero is called as whole numbers. Whole numbers denoted by W.

Formula: n ≥ 0
Whole numbers = Natural numbers + zero

Example: 0,1,2,3...


Integers(Z):

Counting Numbers with zero and –ve numbers is called as integers. All integers are fractions. Not all fractions are integers. Integers denoted by Z

  • Positive Integers: n > 0; [1, 2, 3...]
  • Negative Integers: n < 0; [-1,-2,-3...]
  • Non-Positive Integers: n ≤ 0; [0,-1,-2,-3...]
  • Non-Negative Integers: n ≥ 0; [0, 1, 2, 3...]

Formula: n ≥ 0 or n ≤ 0
Integers = Whole numbers + the negative of the whole numbers.

Example: ….3,-2,-1, 0,1,2,3...

Rational Numbers (Q):

Rational numbers nothing but fraction of real number. Rational numbers denoted by Q. Fractions can be written as a terminating decimal or a repeating decimal.

Example: 22/7, 45/6…

Formula: m/n remainder is not zero
Rational numbers = Integers + fractions

Irrational Numbers (P):

irrational number is a number that perfectly divisible by itself. Irrational Numbers is denoted by P.Irrational numbers are numbers that cannot be written as a fraction. Another way to see them is that they are neither repeating decimals nor terminating decimals.

Example: 22/2, 45/5…

Formula: m/n remainder is zero


Real Numbers(R):

Collection of rational and irrational numbers called as real numbers. Real number is denoted by R.

Example: 22/2, 45/5, 22/2, 45/5…

Formula: m/n
Real numbers = rational numbers + irrational numbers

Even Numbers:

A number perfectly divisible by 2 is called as even number. Alternative numbers from zero is also called as even numbers.

Example: 0, 2, 4,6,8,10,12…

Formula:n / 2 = 0

Odd Numbers:

A number not perfectly divisible by 2 is called as odd number.

Example: 1, 3,5,7,9…

Formula: n / 2 ≠ 0

Prime Numbers:

Numbers which is divisible by itself and 1 is called as prime numbers. 1 is not a prime number.

Example: 2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37, 41, 43, 47, 53, 59, 61, 71, 73, 79, 83, 89, 97

1Q: How to check 157 is prime number or not?
Solution:
Step 1 : 13 > √157
Step 2 : Prime numbers less than 13. So less than 13 prime numbers are 2, 3, 5, 7 and 11.
Step 3 : 157 is not divisible by any prime numbers (below 13).
Result : Finally 157 is a prime number.

Formula: n/n, n/1

Composite Numbers:

non prime numbers are called composite prime numbers. 1 is neither a prime number nor a composite number. 2 is the only even prime number.

Example: 4, 6, 8, 9….

Formula: Natural numbers- prime numbers

Co-Primes Numbers:

Two natural numbers are co-primes if their H.C.F. is 1. For example, (2, 3), (4, 5) are co-primes.

Example: (2,3), (4,5),(4,9), (21,44)..

Formula: 2 number H.C.F is 1

Twin prime numbers:

A pair of prime numbers difference is two are called twin prime number.

Example: The twin prime numbers between 1 and 100.
(3, 5), (5, 7), (11, 13), (17, 19), (29, 31), (41, 43), (59, 61), (71, 73).

Formula: n2-n1=2

Consecutive numbers:

If the difference between two numbers is 1, it is called as consecutive number.

Formula: x, x+1, x+2

Example: 16,17,18,19

Consecutive even numbers:

if the difference between two numbers is 2, it is called as consecutive even numbers.

Formula: x, x+2, x+4

Example: 16, 18, 20

Consecutive odd numbers:

if the difference between two numbers is 2, it is called as consecutive odd numbers.

Formula: x, x+2, x+4

Example: 17, 19, 21

Complex Number:

A Complex Number is a combination of Real Number and Imaginary Number. Complex number is denoted by Im(z).

Formula: a + bi
a, b real numbers
I imaginary number.

Example: √(-7), √(1-8), √(-25) = 5i, etc...

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