Out-of-Band Authentication (OOBA)
Out-of-band authentication (OOBA) is a type of multi-factor authentication which unlike traditional MFA requires two communication channels. This type of authentication is often used by financial institutions and other high-risk organizations to make it much more difficult for a hacker to access systems and data. An example of out-of-band authentication would be using the computer and a smartphone for authentication. A smartphone can be used to receive an SMS code or use an authentication app.

Out-of-band authentication is important in identity and access management because it greatly reduces the chances of what’s called a “man-in-the-middle attack”. In cases of a MITM attack, hackers can take over the communication channel between the sender and the receiver to intercept the communication data. We often overestimate the security of passwords which can be stolen or intercepted during authentication data exchange. Through use of technology, hackers can exploit weaknesses in communication channels to steal authentication data which could expose passwords. This illustrates the importance of using other forms of authentication and verification methods.
Using two different communication channels for authentication in access management lowers the chance of a MITM attack and keeps the transmitted information safe.
Out-of-band authentication can be thought of as a more secure method of 2FA. In a traditional authentication method, 2FA does not have to use a separate communication channel. For example, an email may be used as the second form of verification. While this is more secure than only using a password, the same communication channel is used to authenticate using the second factor. This increases the possibility of system access compromise.
Out of Band Authentication Methods
In a multi-factor authentication (MFA) setting, the system uses at least two different methods to confirm identity. Some methods used to achieve this authentication include:
- Password
- Biometric authentication (fingerprint scans, voice verification, or facial recognition)
- QR codes
- SMS
- Token (authentication app)
- Push notifications
It is important to note that some authentication methods are more secure than others. SMS code messages are among the least secure methods for authentication because they have a higher risk of interception and are susceptible to social engineering attacks.
Out of Band Authentication Implementation
To implement out of band authentication, consider the following steps:
- Identify what needs protection
- Choose the authentication channels
- Identify what users need to use this form of authentication
One security breech can cost a company an average of $3.92 million dollars. The average cost of implementing a strong authentication method is minimal in comparison. Some users might feel inconvenienced by the need to spend several more seconds to log in, however most users are on board as they understand the security weakness in using just a password for accessing systems.
When planning to integrate a strong authentication into a business or organization, there are a variety of providers that can help achieve that goal. Depending on the business, it is important to know if the company has a global reach that offers support and compatibility with different mobile networks, country codes, etc. Quality user support and customer service is extremely important during and after an out-of-band authentication implementation. No one wants to have downtime due to authentication issues, therefore, having the right support when something goes wrong is vital.
There are some regulations which require businesses such as banks to use multiple forms of authentication. For example, in some countries, banks are required to use strong authentication in certain instances such as when accessing an online payment system, setting up an electronic payment transaction, or initiating a payment through a remote channel with increased risks of fraud.
Using multiple authentication channels is a clear choice for any company or organization looking to improve security. It protects customer data and prevents security breaches. It benefits all parties; customers are at a lower risk of stolen data, and businesses have a lower chance of a data breach with major consequences.