Tivo to go?

Tivo popularized digital video recording, but still struggles to make the technology into a profitable business. The company announced its 3 millionth user last month-just as rumors circulated that a bigger company would gobble it up.

The company's recorders arrived at the same time as DVD players, giving buyers an excuse to junk their VCRs. Instead of messing with bulky tapes, owners can store dozens of shows on a hard drive and use an electronic program guide to schedule recordings.

Tivo is now the dominant name in DVRs, controlling an estimated one-third of the market in 2004. Its biggest competitors are those who offer digital recording without the stand-alone recorder. Cable and satellite providers are busily adding hard drives to their converter boxes, while numerous developers offer DVR software for computers.

Tivo fought back by lowering prices and launching TivoToGo, which lets users transfer shows to their PCs. It also invited developers to create third-party programs that run on its DVRs.

Despite all the popularity and innovation, the company is in a management crisis. President Marty Yudkovitz and CEO Mike Ramsay resigned earlier this year, just as the company was working to reshape itself.

Slinging 'hash'

Three Chinese researchers say they've cracked the security code used to protect countless websites. The formula, used everyday in common programs from web browsers to e-mail programs and video games, may face an early retirement.

The National Security Agency developed the mathematical formula, named SHA-1 (short for Secure Hash Algorithm), in 1995 to help generate digital signatures that can identify whether a document is genuine. Most people who use the code never notice it because programmers use it when writing applications.

SHA-1 works by generating "hash," or a string of gibberish text used as the key to unlock a scrambled message. Each document should have a unique hash; if two or more have the same one, this is called a "collision" and it can be a sign that someone breached the security.

The researchers, Xiaoyun Wang and Hongbo Yu of Shandong University in China and Yiqun Lisa Yin of Princeton, found a formula that could find collisions using a supercomputer. They released an abstract of their work last month. The scheme requires enormous amounts of resources and processing power, but the theoretical possibility is enough to make cryptographers look for new options.

Bits & Megabytes

· The FBI warned about a computer virus that spreads through e-mails that claim to come from the bureau. The bogus messages tell recipients that they accessed illegal websites, their internet use was monitored, and they should answer some questions contained in an attached file. The attachment contains the virus.

· A class-action lawsuit in California claims that eBay artificially inflates the prices of goods to increase its transaction fees. Glenn Block, a Pennsylvania man named in the suit, says he was the victim of "shill bidding," after he was coaxed into raising his maximum bid by a company e-mail saying he could be outbid. His complaint does not say how much he seeks in damages.

· Jef Raskin, who designed the original Macintosh computer, died at age 61 after a bout with pancreatic cancer. He joined Apple in 1978 and soon set out to develop a low-cost, easy-to-use computer with a graphical interface. Mr. Raskin named the Mac after his favorite type of apple, but he left the company before his brainchild's 1984 debut following a falling out with company co-founder Steve Jobs.

· Spam is a growing problem for cell phone users, as 43 percent of text messages in the United States are unsolicited junk, according to Wireless Services Corporation, which routes data for mobile carriers. The company says some spammers try to coax users (who often pay for each message) into changing their settings or making expensive long-distance calls.