Compact discs embedded with digital certificates have been introduced in Shanghai as part of an online payment system run by China UnionPay network. Ricky Liu, marketing manager of ChinaPay, software provider for the project, said that discs the size of credit cards were already being used by two Web sites to verify identities of users and secure online transactions. One site is the online storefront for Shanghai House Funding, a home mortgage company, and the other is online gaming site, www.mir2.com.cn . Mr Liu declined to disclose the number of users or transaction volume for the CD cards. Other payment methods recently introduced in the southern part of the mainland by ChinaPay use short message service (SMS) and wireless access protocol (WAP) on mobile phones, although actual takeup was likely to be fairly low, Mr Liu said. The mobile payment technology, developed jointly by Motorola and China Unicom, requires a number of messages to be sent between the user's handset, a payment gateway and the user's bank. 'You could imagine how many would use it, very few for sure. Maybe, after some years, it could be as popular as mobile service today in China, under the condition that all related service from merchants, ISP service, handset technology and banking systems were ready,' Mr Liu said. The CD cards are being tested in Shanghai and will be introduced in other parts of the country by the end of the year. Data on the card, manufactured in China, is digitally signed and encrypted. The addition of a so-called second factor such as a certificate or smart card is often promoted by computer security experts as a way to make online transactions safer than with a password alone, but few banks and online merchants worldwide have taken the extra step. The ChinaPay project, which links the automatic teller machines operated by members, was set up in March by International Commercial Bank of China, China Construction Bank, Agricultural Bank of China, Bank of China, and Shanghai-based Bank of Communications. Members signing on in the past month are HuaXia, Shanghai Pudong Development Bank, Bank of Shanghai, Shenzhen Development Bank and Guangdong Development Bank. ChinaPay's own online payment settlement system, launched two years ago, has signed up almost 200 merchants so far and has annual transaction in the millions of yuan, Mr Liu said.