A one-time password or passcode (OTP) is a string of characters or numbers that authenticates a user for a single login attempt or transaction. An algorithm generates a unique value for each one-time password by factoring in contextual information, like time-based data or previous login events.
Tech support teams typically administer OTPs to people who’ve forgotten their login credentials to an account or website, or when the resource in question requires additional protection from unwanted access attempts. OTPs can also add a second layer of authentication that an unverified user will need to pass before they can access an account.
When authenticating users, companies have to keep three independent factors to keep in mind:
- Knowledge. Things the user knows, like a password, PIN, or security question answer.
- Possession. Things the user has, such as a token, credit card, or phone.
- Biometric. Things that identify the user uniquely, like fingerprints or behavioral data.
In addition to passwords, security teams often distribute possession factors like OTPs using tokens and phone notifications—things the user likely already has.
What are the benefits of One-Time Passwords (OTPs)?
Now that you know what OTPs are, let’s examine how they keep businesses secure.
- Resistance to replay attacks: OTP authentication provides distinct advantages over using static passwords alone. Unlike traditional passwords, OTPs aren’t vulnerable to replay attacks—where a hacker intercepts a transmission of data (like a user submitting their password), records it, and uses it to gain access to the system or account themselves. When a user gains access to their account using an OTP, the code becomes invalid, and therefore can’t be repurposed by attackers.
- Difficult to guess: OTPs are often generated with algorithms that make use of randomness. This makes it difficult for attackers to successfully guess and use them. OTPs may be valid only for short periods of time, require the user to have knowledge of a previous OTP, or provide the user with a challenge (e.g., “please enter the second and fifth number”). All of these measures further reduce an environment’s attack surface when compared to password-only authentication.
- Reduced risk when passwords are compromised: Users that don’t adopt strong security practices tend to recycle the same credentials across different accounts. If these credentials are leaked or otherwise fall into the wrong hands, stolen data and fraud are significant threats to the user on every front. OTP security helps to prevent access breaches, even if an attacker has obtained a valid set of login credentials.
- Easy adoption: One-time passcodes are also easy for organizations to integrate into their authentication strategies. While the cryptic nature of these codes makes them difficult for people to memorize, phones, tokens, and other technologies are widely accessible for security teams to use and distribute to their employees.
What types of OTPs are there?
OTP authentication is possible thanks to tokens. There are a few different types that you’ll come across.
Hard tokens
Hard tokens (as in hardware) are physical devices that transmit OTPs, helping users gain access to accounts and other resources. Hard tokens broadly include:
- Connected tokens: Users connect these tokens into the system or device they’re trying to access. Smart cards and USB drives are inserted into a device’s smart card reader and USB port, respectively.
- Disconnected tokens: The most frequently used token for multi-factor authentication (MFA). While users don’t have to physically insert these tokens, disconnected tokens typically generate OTPs for users to enter. Pocket-size key fobs, keyless entry systems, mobile phones, and banking security devices are some examples of this in action.
- Contactless tokens: These tokens transmit authentication data to a system, which analyzes the information and determines if the user has access rights. Bluetooth tokens are an example of contactless transmission, with no need for physical connections or manual input.
Soft tokens
Soft tokens (as in software) aren’t physical items that we possess. Rather, they exist as software on a device like a laptop or mobile phone. Soft token authentication usually takes the form of an app that sends push notifications or SMS messages for the user to respond to and verify their identity.
All of these methods follow the same basic process: the user sends authentication data to a system, the system verifies if the information is correct, and, if so, grants the user authorized access. It’s the same idea as using a password, but with an OTP the authentication data doesn’t travel or leak beyond the user and target system.
Which authentication methods are the best?
Not all methods are created equal. Implementing any form of MFA marks an improvement over using passwords alone, but each authentication factor offers different degrees of protection. We’ve got some recommendations that’ll help you avoid vulnerabilities.
SMS authentication might be more convenient, but is less secure
We know from our day-to-day lives just how easy it is to communicate through SMS. It makes sense, then, that many companies and service providers have implemented SMS OTP as a second form of identity verification.
Unfortunately, SMS OTP is open to several lines of attack, including:
- SIM swapping and hacking: Your SIM card tells your phone which carrier to connect to, and what phone number to connect with. In a SIM swap attack, a threat actor convinces your carrier to switch your number to a SIM that they own. As a result, they can access all the SMS OTP messages synced to your accounts.
- Account takeover: Many wireless providers let users view text messages within their web portal. If your online account for the web portal is protected only by a weak or common password, an attacker can breach this account and access any SMS OTP messages.
- Lost and synced devices: In theory, losing your phone means you shouldn’t be able to receive SMS OTP messages. However, we can now sync messages between different devices, allowing us to authenticate via SMS OTP and access accounts even without the phone. Forwarding sensitive messages like this isn’t a strong security practice—especially not when your email may have a guessable password.
- Phishing: In a social engineering attack, a threat actor impersonating an employee from a trustworthy service deceives you into handing over your account credentials, and your SMS OTP. Phishing attacks hinge on hackers exploiting users’ emotions or lack of knowledge, and can result in SMS OTPs leaking in the same way as a password.
As more companies adapt to remote work, workforces are increasingly using their mobile devices to access workplace applications. Check out our Businesses @ Work (from Home) report for more insights on how this is affecting security practices.
OTP security tokens have their ups and downs
Hard tokens, like RSA SecureID, are a definite upgrade over SMS-based OTPs—relying on something the user has in their possession makes them less exploitable than knowledge-based authentication. What’s more, an OTP device such as Universal 2nd Factor (U2F) authentication security keys use asymmetric encryption algorithms to ensure that the OTP never leaves the token, effectively meaning it can’t be leaked.
However, the tangible nature of hard tokens also works against them. Users need to carry around another device, which can get lost, damaged, or stolen. This makes OTP tokens challenging for IT to maintain, particularly in large organizations, and can compromise security when in the wrong hands.
Additionally, tokens that must physically connect with a device aren’t always accessible. USB drives like U2F keys, for instance, aren’t a practical solution for securing mobile devices, which don’t have USB ports.
Authenticator apps are a strong alternative
- Mobile authenticators like Okta Verify, Authy, and Google Authenticator verify users by sending OTPs and push notifications to the user’s app. Authentication apps are more secure than the above methods for a number of reasons:
- Mobile OTPs don’t depend on internet access, your location, or the security of your wireless carrier. OTP and push notifications are tied to your device, rather than your number, and they generally work without network service or data.
- Mobile OTP is typically a free feature built into many authenticator apps, meaning it’s easy to use in enterprise and individual contexts.
- Push notifications and mobile OTP codes expire quickly, reducing the risk of exploitation as compared to SMS OTP.
- Some authenticator apps support biometrics such as face and fingerprint identification. This offers a stronger layer of protection—even if your phone is stolen, no one else but you can accept push notifications to the device.
WebAuthn protects even more devices
WebAuthn is a browser-based API that uses registered devices (desktop or mobile) as authentication factors. Biometric authenticators built into devices (e.g., Windows Hello, Fingerprint on Android, Touch ID on iOS) all enable WebAuthn, as can portable devices such as Yubikey 5Ci.
WebAuthn provides some unique benefits:
- Thanks to public key cryptology, it effectively shields users from phishing attacks.
- Integrating with users’ devices and biometrics creates quick and easy login experiences.
- Google Chrome, Microsoft Edge, and Firefox all pair with biometric devices to enable WebAuthn, making it accessible.
Ultimately, we advise implementing mobile app authenticators and WebAuthn, while using other OTP methods as backups.
Learn more
There are many different authentication options to keep your accounts secure. To learn how they compare, check out our factor assurance datasheet.
FAQs
What is your OTP one-time password? ›
One-time password (OTP) systems provide a mechanism for logging on to a network or service using a unique password that can only be used once, as the name suggests. The static password is the most common authentication method and the least secure. If "qwerty" is always your password, it's time to change.
What is one-time password example? ›One Time Password Examples
Once the user has begun his login attempt, filling in his username and the correct password, an SMS OTP is sent to the mobile number connected to his account. The user then enters this code shown on this phone in the login screen, completing the authentication process.
Amazon Pinpoint includes a One-Time Password (OTP) management feature. You can use this feature to generate new one-time passwords and send them to your recipients as SMS messages. Your applications can then call the Amazon Pinpoint API to verify these passwords.
What is my OTP number? ›OTP is a six-digit numerical code sent in real time as SMS to your registered mobile number while performing the transaction. OTP is mandatory for authorizing the following transactions: Registration of beneficiary bank accounts of other banks. Bill payments.
What is 4 digit OTP password? ›The full form of OTP is the One Time Password. OTP is a code of four or six digits that is often referred to as a one-time pin or dynamic password. It is a form of security password which is effective for the payment or single-use which is used for payment on the mobile phone, one computer, and so on.
What are the two types of one-time password? ›There are two types of OTP: HOTP and TOTP.
What does OTP look like? ›A time-synchronized OTP is usually related to a piece of hardware called a security token (e.g., each user is given a personal token that generates a one-time password). It might look like a small calculator or a keychain charm, with an LCD that shows a number that changes occasionally.
What is one-time password for iPhone? ›When you sign in to some websites and apps, a one-time SMS passcode is sent to your iPhone. As a security measure, you're required to enter the code into the website or app. iPhone can detect the passcode in Messages and display it above the keyboard. To use the passcode, tap it.
How do I set up OTP on Amazon? ›Choose Login & Security
Click Edit next to Two-Step Verification (2SV) Settings. In the Enrolled 2SV Authenticators section, click Add new phone or Authenticator App. Complete two-step verification by receiving an OTP via voice call.
- In Your Account, select Login & security.
- Select Edit beside Two-Step Verification (2SV) Settings.
- Click Get Started.
- Follow the on-screen instructions.
How do I stop Amazon from asking for OTP? ›
In Your Account, select Login & security. Select Edit beside Two-Step Verification (2SV) Settings. Select Disablebeside Two-Step Verification.
Does OTP mean in text? ›What does OTP mean? OTP is an abbreviation meaning "one true pair/pairing."
What is the email OTP code? ›The Email OTP method enables you to authenticate using the one-time password (OTP) that is sent to the registered email address. When you try to authenticate on any device, the server sends an email to the registered email address with the OTP.
How do you check OTP is coming or not? ›- Click on 'Resend OTP'
- You might have network connectivity issues. ...
- You may also restart your Android phone to have your network connection refreshed on your device.
- Check with your message permission settings on your mobile and allow SMS access to get the OTP.
- Login to your Online Banking Service.
- Access the Navigation menu.
- Select My Profile ►Profile Management.
- Under Personal Information, select Manage Contact Details.
- Under Actions, select applicable Cell Phone number and click Edit.
- Edit Cell Phone number, and click Continue. ...
- Confirm information and enter OTP and.
There are two ways to create OTPs. One way is through the use of smartphone apps like Google Authenticator, Authy, and Duo. The other way is to generate one-time passwords online using websites such as TOTP Generator.
Is OTP the PIN code? ›An OTP (One-Time PIN) code is a one-time password or one-time PIN. An OTP is a feature of Two-factor authentication (also known as 2FA) security. When a user attempts to access a service protected by two-factor authentication they will be sent an OTP to their phone, to submit as confirmation of their identity.
Is OTP the same as PIN? ›One Time Password (OTP) is used during your registration process and PIN changing process. Please note that your SMS OTP is only temporary and changeable. On the other hand, PIN number is an access code for login and all transactions. Your PIN remains the same and can only be changed deliberately by the user.
What are the two most popular passwords? ›- guest.
- 123456.
- password.
- 12345.
- a1b2c3.
- 123456789.
- Password1.
- 1234.
and once you share the OTP, he would get access to your account. To gain your trust, he might mention that he is from a bank or from a trusted third party. Using an OTP a person can create an account by pretending to be you. That account can be used for the wrong purposes.
Can anyone read my OTP? ›
OTP thefts typically occur in two ways. One, your phone could be infected by a malware, which can be used to tap into your messages containing the OTP. Two, you could get duped into revealing your OTP by a fraudster. You could also be sent links that are used to corrupt your phone.
How do OTP codes work? ›A one-time password is an automatically generated code sent to a known device owned by the user after they attempt to log in. To authenticate themselves, they must enter the code, typically sent via text message or email.
How many digits is a one-time passcode? ›What is a one-time passcode (OTP)? An OTP protects your credit card from being used by anyone else to shop online. It is a unique 6-digit code that we'll send as a text or automated call to the mobile or landline number saved to your account.
What is the most common password for iPhone? ›- 123456.
- 654321.
- 111111.
- 000000.
- 123123.
- 666666.
- 121212.
- 112233.
There is an additional 4-digit PIN next to the agent's contact number, which is only required when you need to contact the delivery agent. Now all you need is wait for the agent to come to your doorstep.
Why am I not getting OTP on Amazon? ›I suggest going to Amazon account settings, deleting your Google Voice number, and adding it back again. If it fails to send you a verification code, then you've got a problem. You can also use Google Authenticator app on Android or iOS devices as a more secure method of authorization for Amazon. Thanks for responding.
Why is Amazon suddenly asking for verification? ›To make sure only you and authorized users have access to your Amazon account, we may ask you to complete an extra step when you sign in. “Multi-factor authentication” happens when your sign-in activity looks different because you've cleared your cookies, or you're signing in from a new browser, device, or location.
How do I recover my Amazon password? ›- Go to Password assistance.
- When prompted, enter the email address or mobile phone number associated with your Amazon account and select Continue. ...
- Enter the OTP you received and select Continue.
- Create a new password.
If you no longer use the email or mobile number associated with your Amazon account, you may contact Customer Service for help restoring access to your account.
How do I turn off 2 step verification without signing in? ›First off, go to Settings and Privacy > Settings > Security and Login > Two-factor authentication on your browser-based Facebook account. You'll find a list of your authorized devices where you won't need to use a login code.
How do I get rid of OTP? ›
In the navigation menu, click Advanced then Security. In the Security section, click the One-Time Passcode Authentication toggle to disable it. If a verification dialog appears, click Disable to verify the change.
Why does Amazon keep asking me to change my password? ›A recent wave of phishing is hooking Amazon Prime members using an email that requests customers to change their Amazon account passwords. Amazon is aware of these emails and shared advice on how to identify these emails. Amazon will never ask in an email for customers to provide : social security numbers.
Why am I unable to access my Amazon account? ›As a part of basic troubleshooting, reset your password by going through our password assistance process on our website. To reset your password: Go to Password assistance. When prompted, enter the email address or mobile phone number associated with your Amazon account and select Continue.
What does op mean on the internet? ›What else does OP mean? On internet forums and message boards, OP is short for original poster, or the person who started the thread that users comment on.
What is the short form for password? ›Password. Pw is a common abbreviation for "password." People typically use pw when discussing login credentials for a computer, app, or website.
What is OTP PIN code? ›An OTP (One-Time PIN) code is a one-time password or one-time PIN. An OTP is a feature of Two-factor authentication (also known as 2FA) security. When a user attempts to access a service protected by two-factor authentication they will be sent an OTP to their phone, to submit as confirmation of their identity.
Is your OTP for phone verification? ›SMS OTPs (also called one-time PINs or one-time passwords) are frequently used to verify a phone number, for instance as a second step in registration / authentication or to verify online payments.
How do I enable one-time password OTP via email or SMS? ›- Open your browser and click the RoboForm extension icon. ...
- Select "Settings" from the menu.
- Select "Security" from the column on the left. ...
- Select SMS and input the phone number you wish to receive the OTP message.
- You will then be prompted to enter the code you received.
A one-time passcode or password (OTP) is a code that is valid for only one login session or transaction. An OTP is typically sent via SMS to a mobile phone, and they are frequently used as part of two-factor authentication (2FA).
What is the difference between OTP and PIN? ›The difference between OTP and PIN
1. OTP is temporary, and PIN is permanent unless the user changes the PIN code. 2. The OTP is generated by the system, while the customer himself generates the PIN and Password.
Why is OTP only 6 digit number? ›
The 6 digit OTP code does prevent replay attacks where the 7 digit password does not. And locking the user out after 10 invalid attempts will add more security to the 6 digit OTP code than the 7 digit pure numeric password because the lockout would invalidate all previous guesses on the OTP code.
What is OTP in Android phone? ›OTP means One Time Password: it's a temporary, secure PIN-code sent to you via SMS or e-mail that is valid only for one session.
Why I can get any OTP on my phone? ›Improper network checks and country code is another means through which the OTP not received issue can occur. Having a good and reliable connection is also vital for receiving OTP. Instances where an OTP couldn't be found in your messages after multiple requests might require connectivity and network test.
Is it possible to bypass OTP? ›OTP are used For extra security layer To secure User authentication but in some case in some vulnerable website We can easily Bypass OTP two factor authentication verification schema On web or application based platform .
What triggers OTP? ›There are two different triggers for OTPs—time-based and event-based: Time-based triggers generate OTPs that are valid for only a certain length of time, often as little as 30 or 60 seconds. Event-based OTP triggers generate OTPs after an event, typically the press of a button, and remain valid until a user uses them.
Can someone access my OTP? ›The popular method of something you have is to send an OTP in a secure token to device. This too has a security vulnerability in that you can still trick humans into presenting this token to fake sites and services. This is because the authentication is one-way, user to server.