VoIP Security Essentials: Key Considerations for a Secure Communication Infrastructure

Over the last few decades, Voice over Internet Protocol (VoIP) has emerged as a leading choice in business communications, establishing itself as the future of telephony. Businesses are becoming more receptive to the idea of making calls through the Internet, with 79.3 million people in the United States being VoIP users. As adoption rates continue to rise, and organisations look to take full advantage of the many benefits of a VoIP system, business leaders have gradually given greater consideration to security and what it means to create a robust and reliable infrastructure.

Understanding VoIP security

There are 800,000 cyber attacks per year, and the average cost of a data breach rose from $4.24 million to $4.35 million across 2021-2022. With these cyberthreats remaining prominent and damaging, it’s not surprising to see that 86% of businesses were set to increase their spending on security throughout 2023. As VoIP becomes more widely used, it’s more important than ever to understand what leading VoIP solutions can offer in terms of security, and what steps can be taken to stay safe from external threats.

Common threats to VoIP security

The cost-effective, highly scalable nature of VoIP and its ability to enable hybrid working has certainly influenced its wider usage, yet its reliance on the Internet opens up multiple avenues of attack from external forces. Cyber criminals have the capacity to damage a business by breaching security infrastructure and causing chaos through stealing sensitive data or intercepting calls. It’s important to understand what tactics these nefarious types could attempt to disrupt daily business operations, including:

  • Malware, which can jeopardise bandwidth and cause a breakdown in signals after users unwittingly open a harmful link and release the software
  • Distributed Denial-of-Service (DDoS), designed to overwhelm servers with data, use up existing bandwidth, and bring all calling activities to a grinding halt
  • Voice Over Misconfigured Internet Telephones (VOMIT) and the conversion of phone conversations into a transferrable file that gives hackers the ability to eavesdrop and steal sensitive information, such as passwords and call origin
  • Spam over IP Telephony (SPIT), with hackers calling or leaving voice messages as a way to redirect recipients to expensive phone numbers abroad, or unleash malware
  • Phishing, or ‘vishing’ when concerned with voice, sees cybercriminals attempt to trick companies into departing with sensitive information under the guise of being a reputable business themselves

The methods of infiltration are both many and costly, especially when VoIP security is not taken as seriously as it should be. It can be dangerous to be complacent when sensitive data and reputation are on the line. There are, however, various methods and procedures that VoIP systems can implement to protect business interests and ensure no dangerous external threats breach and disrupt.

Bolstering VoIP security

Being ready to address these concerns is the best place to start when building a secure IT infrastructure that doesn’t jeopardise daily business operations. Even though the amount of small businesses placing a high priority on cyber security has dropped from 80% in 2022 to 68% in 2023, it remains a topic of great concern for business leaders – and so it should! But when it comes to bolstering network security, what kind of measures can be taken?

A key building block that forms this infrastructure is encryption, which can be utilised in two distinct formats. Secure Real-Time Transport Protocol (SRTP) applies the Advanced Encryption Standard (AES) to data packets that are in the process of being transferred, providing additional confidentiality, protection against replay attacks, and message authentication compared to Real-Time Transport Protocol (RTP). VoIP providers can also deploy Transport Layer Security (TLS) to scramble sensitive data and add additional layers of verification to encrypt data between two endpoints. Considering 1 in 4 Wi-Fi hotspots aren’t encrypted, it’s always a good idea to choose a VoIP provider that can encrypt those sensitive pieces of data!

Firewalls are also a useful ally in VoIP security, with these tools able to track incoming and outgoing traffic that grants greater control over who can access data. With a firewall in place, data packets undergo a thorough inspection for any kind of malicious threat which can pose a danger to sensitive information. Tracking that traffic negates any potential ‘Trojan horses’ entering a system and taking control, while also blocking hackers trying to force themselves into the network and detecting insider attacks (which 98% of companies feel vulnerable and susceptible to). But firewalls are just the first step, especially when remembering the importance of securing Session Initiation Protocol (SIP) technology.

From the start, it’s worth noting the differences between SIP and VoIP; in simple terms, VoIP enables Internet-based calling, and SIP allows devices to make these kinds of calls. This portal, while integral to VoIP’s functionality, wasn’t exactly designed to be secure, opening it up to its own threats if not protected properly. Caller ID spoofing (impersonation to gain sensitive data) and Wangiri Fraud (tricking users into calling expensive premium-rate numbers) are just two ways that hackers can disrupt SIP and, in turn, VoIP calls.

A Session Border Controller (SBC) can be deployed between a public and private network in order to deliver data packets to the correct endpoint. SBCs add reliability, quality of service and ,most important, security to a telephony network due to their control over communication sessions. Leveraging such a method can take both security and communications in general to a whole new level.

The offerings of VoIP providers, of course, is just one half of the story. It’s down to businesses to instil a sense of ownership and care amongst their employees when it comes to cyber security, while also taking the right steps themselves. There are a number of practices to keep in mind when securing communication infrastructure, including:

  • Regularly updating VoIP systems and end user devices to maintain functionality and security
  • Monitoring call logs and identifying unusual trends, such as abnormally long calls or odd hours of operation
  • The implementation of two-factor authentication and the usage of strong passwords
  • VPN usage for all remote employees
  • Better educating staff to be aware of the signs of security breaches, as well as how to enact a crisis management plan if such an event takes place.

With all this in mind, businesses are more than capable of creating a telephony infrastructure that is secure and ready to deal with these external threats. But that’s just the here and now – we need to talk about the future.

The future trends in VoIP security

In 2021, the global VoIP market was valued at $85.5 billion; by 2026, it will be worth $102.5 billion. It’s clear evidence in how fast VoIP will grow as part of communication infrastructures, and its future certainly looks bright. Technological innovations, including 5G and its emerging domination of the mobile market, open up a whole new wealth of opportunities for VoIP through enabling hybrid working or its impact on the Internet of Things (IoT). But the more popular VoIP becomes, the greater the risk comes in regard to cybersecurity.    

In 2019, 50% of CEOs in the United States were ‘extremely concerned’ about cyber threats, which is no surprise considering the average cost of a data breach totals $4.45 million. Artificial Intelligence (AI) has fuelled ‘fake news’ and the spread of deep fakes across the Internet, and Cybercrime-as-a-Service just poses another risk to any system. Malware, phishing and DDoS become the norm for these dangerous individuals, and knowledge gaps in cybersecurity knowledge pose a great threat to maintaining security. Remote working only makes the need to secure all end points of an infrastructure even more important, with setting up VoIP phones at home now part of the wider VoIP adoption. It’s certainly the future of business communications, but it can only thrive when security is prioritised.

Making sense of the importance of VoIP security

VoIP phone systems are going to continue evolving and adapting to the growing needs and demands of a business, no matter the size of the enterprise or the scope of the products it supplies. What all of these businesses that are utilising VoIP have in common is that they are subject to the multiple security threats that can cause havoc and extract critical pieces of data. Going with a trusted VoIP provider guarantees that security is paramount, deploying methods such as encryption and SBCs to keep cyber criminals out. Businesses must also take it upon themselves to educate their employees over online safety and be aware of the risks they could face.

VoIP is poised to be the muscle behind the next step in business communications, but only through a rigid and secure infrastructure can VoIP’s potential be fully recognised.