As more businesses adopt ISDN adapters and routers, which decrease costs by letting users share bandwidth, people working at home may choose cable modems. They let users access data services through the same wires that transmit cable-TV signals. The nascent cable-modem market presents a few potential downsides. Foremost are unresolved security issues. Because dozens or even hundreds of cable customers share cables for these devices, they are relatively easy to attack.
Hackers can use sniffers, and the more aggressive attacker can physically tie into cable lines.
Some cable providers offer security services, such as installing in cable modems filters that are supposed to make data from one customer invisible to others. However, the effectiveness of cable companies' security efforts has not been established. Although most burgeoning modem technologies attract users with promises of more bandwidth, one new type concentrates solely on low price. Software-based modems, also called soft modems, use a computer's CPU to perform modem functions. Because many applications, such as word processing, make only marginal use of high-end processors, there's enough power left over to run a modem.