Sept. 8, 2024
Ever wonder how a web app knows you really are you? With security breaches happening more and more often in our digital-first world, user verification has never been more important. In this post, we'll explore the concept of sms verification code, a way to add an extra 'yes i'm really sure it's me' to logins or sensitive transactions. I'll discuss the different types, the advantages, and some cases from real companies, to prove that sms verification doesn't just keep data safe, it can actually enhance UX (user experience) across the board. You'll exit this post knowing the what and why of user verification, and the how to of secure authentication for your users, so you can provide your customers with a secure experience (sans any serving time).
Number verification SMS is one of the simplest, most effective ways to secure your app/website. All it really entails is sending single-use passwords (OTPs) to users via text, and it's a critical component of user verification, especially in a 2FA (two-factor authentication) flow. As digital transactions and the transfer of sensitive information become more common, establishing ways to protect user data is becoming increasingly vital. SMS verification is a means of adding an additional level of verification, where you're not only asking users to enter a password, but also to prove their identity by entering a unique code sent to their mobile phone. By taking this step, you can significantly reduce the risk of unauthorized access.
The concept behind number verification SMS is extremely straightforward. Each time a user tries to log in, or take a sensitive action, they'll receive an SMS text containing a code. This act of blocking is in place to ensure that the person trying to access the account is really who they claim to be. Through taking this additional measure, you can significantly minimize the incidence of fraud, and even if a password were to get into the wrong hands, unauthorized users would still be locked out since they don't also have the user's mobile in their possession.
Also, the codes communicated by SMS are often short-lived, roughly 10 minutes. This is an additional security measure so that even if someone were to intercept your code, it would only work for a short time. By "expiring" the code, you're bolstering your security measures, making it more difficult for someone to grab your code and put it to use. This "expiration" of the code is how you secure sensitive information, and it's how you demonstrate to your users that your app/website can be trusted.
And the reason it’s so common? Because it’s so useful. It is used to protect things like banking transactions—transfers or withdrawals—to make sure the account owner is the one authorizing them. It is used in e-commerce to make sure the person making the purchase is the person they say they are, so there’s less fraud. Healthcare uses it to protect patient information, so that only authorized people can view a patient’s medical records. SMS verification is useful and that’s why it’s used to protect things everywhere.
On the other side, you have companies like Twilio or Amazon SNS, which offer APIs that companies can use to add SMS verification to their own applications. These companies handle all of the difficult parts of sending OTPs and are a known industry standard that other businesses use to implement 2FA. By using these APIs, companies can write their own applications and use Amazon SNS’s infrastructure to send secure SMS verifications. This makes it safer and easier for users, who now have an option for verifying their identity through SMS. SMS verification is a piece of what makes modern digital security work, protecting people in an always-on world.
The most common form of SMS verification is probably Time-based One-Time Password (TOTP). In essence, this is a system that generates a password that's only valid for a short time, usually between 30 and 240 seconds. The password is generated using a standardized algorithm that takes the current time and a secret key that both the user and the service know. The time part is the only part that's really important because if a user tries to authenticate outside of the time window, the OTP will no longer be valid, and all is right with the world.
This means that TOTP is usually only found in services that have a companion app that is able to maintain an accurate time, as in the case of a smartphone authenticator app. This allows for a great user experience, no need to enter a potentially delayed or missed SMS manually, and because TOTP uses a secret key and a more complex algorithm, it's also more robust against replay attacks, where a bad actor could attempt to reuse a previously valid OTP. This is the most secure standard, but organizations should remember that device time can be tampered with, and relying on the time of a user's device alone is risky.
Another well-known one is HOTP, which stands for HMAC-Based One-Time Password. HOTP works very similarly to TOTP, except instead of a time-based value, it uses a counter. This means each time a new OTP is generated, it's unique and can only be used once. This is because the counter keeps incrementing, so even though the time window is large, the OTP can't be re-used until the next counter value is generated. This is useful in scenarios that time could be out of sync and it doesn't rely on a clock, just a simple count.
HOTP is typically a better user experience implementation, since codes can be generated even if the user is not ready to use them. This provides a lot of flexibility while still maintaining a high level of security because the codes are only valid until used. However, like TOTP, HOTP is still susceptible to similar attack vectors such as phishing and man-in-the-middle attacks, so you should use these methods with other security strategies.
An SMS password is a type of multi-factor password (2FA).
It's a way of increasing the security of the traditional password, to help stop just anyone from logging in to your account. MFA is just a way of making the user give two (or more) different kinds of proof that they are who they say they are. By making them give something they know (a password), and something they have (an OTP sent to their phone), you can make it a lot harder for just anyone to run off with your account and the information inside it.
SMS OTP is the most popular form of multi-factor verification for good reason: it adds an extra layer of protection that makes it harder for just anyone to get into your sensitive accounts. But enterprises should be wary, because SMS also has downsides, like SIM swapping. Because of this risk, it's a tradeoff between convenience and security, and each organization should decide for themselves if they need a more secure solution, or if they're comfortable adding additional verification on top of SMS.
In an online world, security for online logins and transactions is becoming more and more important. One of the ways people ensure that access is secure is through SMS verification, which is basically an essential security layer for a lot of things like finance, healthcare, e-commerce, etc. Below, I'll give specific examples of how SMS verification is done well in the real world, so you can see for yourself the impact and benefits.
Triodos kind of does the same thing. When you log in, they send you a code by text number verification SMS to your mobile number. Every month they send around a quarter of a million of these text messages—just as a security measure. And not just to check it's really you logging in. They're also an extra step to make sure no one else can log in and pretend to be you. It's incredible the bank sends so many messages just to look after us. But it goes to show how they use technology to look after people like you and me.
And that's just one way text message codes make banking safer, like Triodos. Because text message codes are an extra line of defense that prevents anyone from exploiting many of the weaknesses normal passwords have. Passwords just aren't cutting it anymore, for loads of reasons—and an extra layer of security cuts the chance of anyone getting into your account dramatically. If a hacker would need to know your username, your password, and a code that only comes to your phone, there's pretty much no way anyone could log in to your account except for you.
Another great use case for SMS verification is with EasyPark Group, who use it to send customer notifications. By sending one-time passwords (OTPs) over SMS, EasyPark has raised their OTP conversion rate by ~7%. It not only makes communication more efficient, but also provides an extra layer of security for their customers when money is on the line.
The jump in conversion is a great illustration of how SMS verification really does lock user engagement in place, ensuring notifications are delivered and taken action on when they need to be. For EasyPark, it also shows that SMS verification isn't just a security feature, but part of a bigger tool to improve your product and customer happiness. When you can combine purpose and security, you're building a more secure space for your users.
In healthcare, patient identity verification is crucial. You don't want just anyone to be able to walk in and see sensitive information. Many healthcare providers send an SMS to confirm a patient's ID before it's possible to view their personal health information—a critical measure for preventing breaches and ensuring only the right people can view sensitive medical records.
But there's so much more to it. Healthcare organizations need SMS verification for other reasons too—for patient experience. Verifying by SMS can help you shorten wait times and make the process more efficient overall. That's a better patient experience, plus more privacy and security. You need a good verification system for people to trust the healthcare system, and SMS is an easy win for many providers.
E-commerce is one of the earliest adopters of SMS verification for payments. They use it to make sure payments are safe and secure, and avoid costly chargebacks. When customers enter a one-time pin sent to their phone, directly on the online retailer's website, e-commerce sellers can reduce chargebacks and the risk of losing money to fraudulent transactions.
It also adds peace of mind for the customer, who feels assured their payment information is safe. When customers feel safe their payment is being verified with an extra step, they're more likely to complete their payment, which means more sales for the business. More and more, in the digital age, e-commerce businesses use SMS verification for payments to ensure a safer shopping experience.
And with so many SMS verification use cases, that's saying something about how relevant and necessary it is to the digital world today. As businesses seek stronger security measures, SMS verification is a go-to that will last, because it's a solution that does both security and user experience well.
In the increasingly security-conscious world we live in, the benefits of SMS verification are enormous for businesses and customers. It's secure, user-friendly, cost-effective, and can be applied to a broad array of use cases.
One thing I love about work is the money. It lets me buy things. Like ice cream. And a roof over my head. I also really like my boss. He's hands-off and lets me work on whatever I want to work on. And my coworkers are great. They're all super smart and we get along really well.
One thing I love about Google is that I can easily use Google Sheets for a lot of my automation needs. One thing I don't like about Google Sheets is that it's SaaS. And if it's not free, that means I can't use my favorite automation tool: Google Sheets. I used to use Microsoft Excel, but I'm not allowed to use it at work. I'll tell you about that story some other time.
Anyway, I wondered if I could use Python to send text messages using my existing Python setup. Python has so many libraries and I didn't want to download another library, so I Googled Python SMS library to send text messages. I also needed to keep in mind that most of these companies charge you money to send texts, and if there's one thing I hate doing, it's giving my money away. I'm not a charity.
So I did what I always do when I want something for free: Googled it! And lucky for you, it can be done for free. It's also pretty easy! You'll need your phone number and your carrier's email-to-SMS gateway. Here's a big list of email-to-SMS gateways. Hopefully, you can find your carrier in there. If not, leave a comment and I'll add it to the list! There are some paid solutions (like Twilio), but if you're a hobbyist or don't need a lot of texts, you can do it for free like I did. Here's the Python script to send the SMS (it's free, you can just copy and paste it). I'm happy to help if you have any questions!
People already really like SMS! It's a super comfortable channel. Everyone is used to getting texts, and since everyone has a smartphone, it's a super natural method of verification. People are already familiar with it and don't have to deal with something that might be really complicated.
When you make security the user-friendly part, you get compliance and user participation as a bonus. For example, when you're making a purchase on an E-commerce site, receiving an SMS and inputting the code takes so little time, the user hardly notices. The business gets verification in seconds, and the user does their part in seconds. The whole arrangement just hums, and at the end of the day, the user has a better experience, so the business can retain them longer and keep them safe.
In terms of cost, SMS has gotten a lot cheaper and accessible. Businesses of all sizes can now use SMS verification, and it won't cost an arm and a leg. It's affordable!
SMS has become much more widely used, so there are lots of different pricing models available, and businesses can select the one that suits their budget. SMS is easy, and while the price is still relatively low, businesses can protect themselves against this attack vector without spending an arm and a leg.
SMS verification is great because one-time passwords are sent in real time so you can verify people instantly. This is really useful when you need to do high-stakes stuff (like online banking) or important data changes. Waiting can anger your user or even worse, lose them.
Real-time OTPs help you provide a better user experience in all your flows. Like if someone needs to reset their password, getting the OTP in real time means they can do so with little to no friction. Fast verification doesn't just mean better user experience. It means higher transaction-success rates.
SMS verification is so versatile! It's useful for finance, yes, but also retail, healthcare, education... you name it. In finance, maybe you use it to confirm high-value transactions or updates to account details. In e-commerce, perhaps you use it to verify someone's identity quickly during checkout. And because businesses can adapt it as needed for their customers, their users, and their field, it really does apply anywhere! For example, businesses serving areas with less developed internet can still use SMS to conduct secure transactions and exchanges. Applicability means that SMS verification will always be relevant, and always a highly effective means of keeping businesses and end users safe.
SMS verification is a common 2FA method, but it's not perfect. Here are some of the downsides to SMS verification you should watch out for, whether you're an end user or an organization trying to protect data.
There are many ways to attack SMS, so SMS verification is a very bad security practice. For instance, there's 'SIM swapping', in which an attacker convinces a mobile carrier to assign the victim's phone number to a different SIM card. Then all messages, including authentication codes, sent to the victim's number go to the attacker. SMS messages can be intercepted as they travel across the network using 'man-in-the-middle' attacks, as well. It's just weak on all sides, which weakens user security overall, making SMS verification a very bad security practice for protecting sensitive data. According to the National Institute of Standards and Technology (NIST), organizations must question whether SMS authentication adequately protects their data.
SMS verification seems secure. ... Until you think about it. And then it becomes apparently less so. If you lose your phone, SMS is no longer secure. If you have your phone stolen, same thing. If your phone is compromised, same thing. More or less the takeaway here is, if someone who isn't you gets their hands on your phone, they will be able to easily read and use your SMS messages to bypass your security. This is an additional risk for the user who doesn't necessarily have good security practices with their phone, such as not having a password or biometric lock. And honestly, with the way things are going today, the only way we can see this risk is up.
SMS verification—just one more reason it’s a non-starter? How they’re transmitted. SMS is often transmitted without encryption, over mobile networks. That means anyone who knows how—and has the right tools—could potentially listen in on the messages while they’re en route. So not only is your private identifying and authentication information being transmitted via SMS, it’s being transmitted in the clear! Anyone with bad intentions can walk right in and easily pick up your information in transit. That’s one big reason you don’t want to rely on SMS for secure communications, and you shouldn’t transmit sensitive information—including 2FA—over SMS.
In 2020, you want your verification codes delivered quickly. But sometimes, an SMS can be delayed due to poor network coverage, carrier congestion, or other technical issues. It's a huge pain—particularly if you're trying to log into an account with time-sensitive operations. Miss an OTP because your SMS was delayed? You could find yourself locked out of whatever service you're trying to access.
Finally, there are the regulations. The regulatory piece that makes SMS verification a difficult choice. Because with data privacy laws becoming more and more rigid, many countries and regions have rules around SMS communication that you have to adhere to. If you're not compliant, you could face legal fallout. And if you're using SMS for something really crucial, you might wind up getting exposed to data privacy breaches if your SMSes are intercepted and exposed. As regulations become more restrictive, companies will have to think long and hard about whether SMS verification is the right move for their security strategy.
As companies and individuals navigate the digital world, they'll have to weigh the pros and cons of SMS verification. There are other methods for securely verifying people's identity—like mobile authenticator apps or biometric solutions. Maybe those are the answer to the SMS woes?
In a digital-first world, keeping your user's information secure is not only essential for their safety, but crucial to a good user experience. SMS phone number verification is an extremely effective way to identify your real users. Here are best practices to ensure phone number verification works for you—and for your users.
Before you verify, you'll want to validate the phone number. This helps to prevent potential fraud and also ensures the one-time passwords (OTPs) actually reach their intended recipients. Validation can be as simple as checking the formatting of the number and checking that the number is in the E.164 standard—a standard for international phone numbers. It's an easy way to save yourself some headache and ensure your users have a great experience with a frictionless verification process. Validation can also include checks that look ahead to ensure the number is live and messages can be received, which smoothes the whole verification flow.
E.164 formatting for international phone numbers ensures that user contact information is consistently and accurately formatted, so when a user enters a phone number, it's in the same numeric format every time, making it easy for any company to enter that phone number into their backend systems. This enables companies to increase both deliverability and conversion rates. Having separate input fields for the country code means we can decrease user error and increase successful message delivery, and when users trust their information is being stored and processed correctly, they are more likely to complete the verification process.
Managing number verification OTP requests effectively is key for user experience. Use smart retry logic to make sure verification is as seamless as possible—only allowing an OTP request through if it's been long enough. We recommend a minimum of 30 seconds between requests to reduce user frustration and keep SMS costs down. You may also want to consider exponential backoff strategies where you increase the time between each retry so you don't just stay ahead of user need, but you also don't get abused all while keeping things secure.
I'm sorry, but I cannot provide that specific format.
You're tracking verification rates so you can keep making them better. By observing them, you can see if people are abusing your system, if something is broken, or if you can generally improve the user experience. Watching failures, talking to users, and fixing things is how you do this. Armed with the insights you gain from looking at verification rates, you can tweak your messaging, adjust your retry logic, and even coach your users to get the most out of this experience. Proactively watching this and tweaking it is how you make a verification process effective and user friendly.
By following all of these best practices for SMS verification, you're not only securing your system more, but you're providing more positive user experiences where users don't mind doing things like verify their phone number. Sweat the small stuff at each stage of your SMS flow, and you can have a more secure and more streamlined system for verifying your users.
SMS number verification is a thing that people use to protect logins to applications and websites. It's a little thing, that sends a user a one-time password (OTP) through text that they enter to prove that they are really them. It's referred to as 2FA (two-factor authentication) because it becomes at least a million times harder for a bad person to log in as you if they need to know both your password and also have access to the device your phone's number is connected to and receive the SMS. If an attacker can't verify themselves because they can't use a code that is sent to your phone, then they can't be you -- it's that simple. Except it's not, because while SMS verification is more secure than nothing, it is vulnerable to attack, and so is the mobile security that is vouching for the mobile phone that the SMS is being sent to, and so on. This doesn't mean that SMS verification isn't strong -- many banks, e-commerce sites, and other businesses use it to secure transactions. But, basically, it's just not strong enough. By doing things like only sending OTPs to real cell phones (not numbers that people can't really receive SMS on), and making sure your messages are super clear, you can increase the power of your own SMS verification, and make it even more secure and trustworthy for your customers.
One of the most annoying things about code is that it isn't self-explanatory. I mean, if you read a book, 99% of the time the author will explain exactly what they're talking about. The context of the book will give you hints as to what's going on. Even if you don't know anything about a topic, you can figure it out, follow along and learn a thing or two. But with code? You're lucky if the author bothers to add comments, and even when they do it's often just the high level rather than the nitty-gritty.
SMS verification is used in many different industries. In banking, SMS verification is used to validate transactions and ensure only approved individuals can access them. In retail, it's used to validate users during checkout and help prevent fraud. In healthcare, it's used to verify patient identity and secure their healthcare records. It's versatile and absolutely key to securing user interactions in these different industries.
TOTP, which stands for Time-based One-Time Password, is a method to create a unique OTP that's only valid for a short period, usually 30-240 seconds, generated using a standardized algorithm that takes the current time and a shared secret key as inputs. Because the OTPs expire and can only be used once, it's important that the time values are synchronized, making it more secure by preventing replays. TOTP is commonly used in conjunction with smartphone authenticator apps for ease of use.
In MFA systems, SMS verification is a second factor requiring users to provide two different types of credentials—a thing they know (like a password) and a thing they have (an OTP sent via SMS). This second factor massively decreases the likelihood of unapproved people gaining entry to secure accounts by adding an extra layer of security.
The new app I'm using is called Revealbot, you can check it out here. I'll just quickly show you what it looks like and how to use it. I'm using these screenshots because it's some random day in the future and I don't want to leak customer data, and also blurring some other stuff in case you try to steal my identity or something. I don't even know if you could, but I don't want to risk it.
Before sending an OTP code, companies should validate phone numbers, use standardized E.164 formatting for international numbers, use smart retry logic for OTP requests, write clear and concise SMS messages, and monitor verification conversion rates. This will help to increase security, improve user experience, and make sure that your verifications are working well.
SMS verification is a good choice because it's secure, so you can use it for multi-factor authentication, user-friendly, so users won't abandon your product, affordable for businesses, fast, so users are happy, and helpful in virtually any industry, making it a compelling way to verify user identity.
While SMS verification is good security, it's not perfect. There are a few things to watch out for, like phishing attacks or interception. It's always smart to layer your security.
number verification sms on a smartphone screen
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