You’re probably not a stranger to those SMS with the text “OTP” in it. They often come with registering to a new website or platform or attempting to access a digital banking service. Yes. Sure, you remember. Today, we’re looking at the nitty-gritty of this simple but essential form of digital security.
What is OTP?
OTP, short for One-Time Password, is a type of verification involving a code which can only be used once.
In addition to this, many digital platforms put a time limit on their OTPs. This makes sure that the OTP can only be used once and secondly, that the OTP is rendered permanently useless if not used within a specified timeframe.
How OTP Works
A typical scenario for the use of an OTP is where a website or platform tries to confirm that an activity, such as a login attempt, is being performed by an authorized user.
The confirmation involves sending a code to one or more digital devices or addresses operated by the registered user.
Once sent, the platform then asks the user to input the code which was sent to their linked device or digital address.
If the inputted code matches what was sent to the linked device, then the platform assumes that it is the registered owner who is trying to gain access to the account. This completes the verification process and gives the green light for the user to continue their action.
Alternatively, if the user inserts a code that does not match what was sent, the platform might temporarily restrict access and block all activity.
A comprehensive look at the account security will be undertaken to determine if a comprise has occurred and what the next steps for account recovery and protection should be.
Means of Receiving OTPs
There are two major channels through which a user can receive an OTP. There’s the hardware channel and there’s the software channel. We’ll start by looking at the latter.
Software OTP Channels
The software OTP channel presents four different means. Users can choose to get their code through one or more of these means. They include
Email:
An OTP could be sent to a user’s registered email address. It often takes only a few seconds for the code to arrive after it has been sent from the website or application server.
Call:
Users who provide their phone numbers can choose to receive a call in which an automated machine spells out their OTP. The automated speaker might say the OTP once or twice. The user must get in a good position to properly hear the code.
SMS:
SMS is probably the most popular option for receiving an OTP. It works well for users who do not have an internet connection. However, the SMS option may not work well for time-based OTPs since the message might take more than a minute to arrive.
OTP Generator Software:
Not every online platform makes available a distinct OTP generator for its users. Nevertheless, some do. Certain banks - for example - provide OTP generator software which is distinct from the internet banking app and can be downloaded and accessed like any other application.
At the press of a button, the OTP software generates a code and displays it onscreen to the user. While this happens, the software also sends the generated code to the server of the platform or website which the user is trying to access.
It is the responsibility of the user to copy the code from the generator software and input it on the website.
Hardware OTP Channels
A hardware token refers to a physical hand-held device that generates an OTP at the press of a button. The token device has a small screen for displaying OTP codes.
Like in the case of the generator software, the OTP is sent to the base website or platform which verifies the user’s input to grant them access.
Different Types of OTPs
OTPs work on one principle. It is the exchange of code between a server and a user. To ensure security, the server often verifies that it is interacting with the user’s registered email, phone number, or device. This code-based verification works in two different ways. Here’s what they are:
Common OTP:
This is the typical one-time password that is sent from a website or digital service provider. The recipient comes on the website or platform, inputs the code, and regains access to their account.
Reverse OTP:
A reverse OTP works inversely to the typical OTP. In this setting, the server displays a one-time code to the user who is required to send the exact same code to an email or phone number controlled from the server side.
There’s one thing to point out about this. The user must make use of their registered email, phone numbers, or devices when sending the code.
Pros and Cons of Common and Reverse OTPs
It doesn’t seem like there are disadvantages to using OTP right? Well, you’d be surprised.
Pros of Common OTP
The first advantage of a common OTP or any OTP for that matter is that it protects against replay attacks. This means that hackers who succeed at acquiring a user’s OTP cannot reuse it for subsequent attacks.
Unlike traditional passwords which remain unchanged, OTPs are random. This, in addition to the fact that online platforms may require OTP authentication multiple times within a login session, makes this form of security highly reliable at stopping hackers.
Moreover, OTPs are sent to the mobile device of a user either through a call or SMS. These methods of delivery work without an internet connection making it more difficult for traditional hackers to intercept them.
Cons of Common OTP
An OTP generator or the website server distributing OTPs to users may be out of sync. Imagine that the the server is slower than the code generator, or that the server issues a time-based OTP that continuously arrives late at the user’s end.
Such unsynchronization or delivery delays could cause a serious problem where the user is unable to authenticate themselves.
On a different note, if a hacker repeatedly inputs wrong OTP codes, the user’s account will get locked and the owner of such an account might never regain access to it.
Pros of Reverse OTP
A reverse OTP engages the user, therefore, creating enhanced security and delivering a sense of control.
Cons of Reverse OTP
The reverse OTP presents charges on the user’s side as they have to spend resources for SMS, email or a phone call. In addition, it is more likely to see a human side error because the process is a little more complicated than in the ordinary OTP.
Conclusion
Chances are that you thought less of OTPs and their significance in terms of maintaining account security. We believe most of that has changed now.
In closing, we want to emphasize the need to treat OTPs like regular passwords, keeping them safe and away from third parties. This will ensure that your account is secure and you don’t run into any issues on the platforms you are registered to.