Webmaster Articles: VoIP Security

What is phone phreaking?

Phone phreaking means hacking telephones; this can include the hacking of calls, devices and telephone networks.

What is Voice Over Internet Protocol (VoIP)?

VoIP is a method of transferring voice-based telephone calls across the internet. Telephone conversations are stored in data packets and sent over the internet just like any typical computer data may be.

The Threat of Phone Phreaking with VoIP

While old methods of phone phreaking rarely work on modern telephone systems, the most popular conversion to Voice Over Internet Protocol (VoIP) brings new opportunities for phone phreaking and therefore new risks to telephone users.

VoIP offers the opportunity for hackers to intercept, access and manipulate data from internet-based telephone calls. Hackers can then choose to allow or disallow the intended recipient to access the original, untampered-with data, while sending any modified data as desired to any unsuspecting victim.

Who and what should VoIP users trust?

Everyone and everything; but always with a pinch of salt.

Caller IDs can be easily spoofed and callers voices can be manipulated with audio editing software, allowing familiar and trusted voices coming from familiar and trusted telephone numbers to potentially by the work of hackers and thieves who may be stealing credit card details or other personal information, or even your entire identity as recognised by your government.

While computer security experts warn that VoIP is more prone to eavesdropping than landline phone systems, the FBI warn of VoIP being a potential 'haven for criminals, terrorists, and spies' because VoIP is apparently more difficult for them to wiretap than traditional phone calls. Although rather contradictory, both are warnings and should be duely heeded.

Denial of Service (DoS) attacks on VoIP

Shutting down a large organisation's telephone network is easier than even before if they're relying on VoIP. All that is required is a simple Denial of Service (DoS) attack to flood the network with more data than it can handle, thus denying its ability to provide service.

Many Internet Service Providers (ISPs) have already been convicted of flooding their VoIP-providing competitors.

Backup with a landline

As VoIP telephone service relies on computers and the internet to keep running, if a power outage occurs, whether due to natural disaster, deliberate sabotage or otherwise, then a VoIP system may be dead while a traditional landline system running on a seperate power grid would probably still be operational.

Few adept internet hackers would struggle to take down a major VoIP network. Toppling a landline network, however, is likely to require rather more specialist knowledge.

Spam Over Internet Telephony (SPIT)

With VoIP, hackers and spammers can now send telemarketing enquiries to private phone numbers, encouraging people to pick up the phone and reply because the calls are coming from familiar numbers, and possibly even from familiar voices!

How to protect yourself

Presume nothing.