DMCA
Digital Millenium Copyright Act(DMCA)数字千年版权法案，大致上就是禁止任何人散布可“回避”著作权保护机制的软硬件,美国一联邦上诉法院也曾判决,与回避软件的任何连结均为非法。但一般认为,该法允许回避方式的理论性探讨。
DMCA安全认证系统遵循国际PKI系列标准,按照ITU-T x.509国际标准实现,可发放各类符合x.509标准的证书,同时该系统考虑兼容SSL.S/MIME等格式的证书,该系统支持Netscape和微软的WEB服务器和浏览器,能够满足各种不同的业务需求.
DMCA安全认证系统可以针对不同类型的用户,如企事业单位、服务器提供商、服务器、个人等发放不同安全级别、不同用途的数字证书，满足网上各类业务（包括支付类和非支付类）。
例如安全电子邮件服务、电子报税、电子证劵、电子银行、电子商场、代缴代付、银行转帐、银企对帐、网上防伪打假等众多业务的安全需求，并且可以用于政府上网工程中的安全政务系统，以保证网上公文传送的安全性。
该系统采用可以保证网上电子商务业务敏感数据传输的安全性（数据未被窃听）、数据的完整性（数据未被篡改）、身份认证和交易的不可抵赖性等。
In 1998, the Digital Millenium Copyright Act (DMCA) was signed into law. Within its pages laid many changes to the current copyright law, most created to help fight burgeoning piracy on-line. Since its passage, the DMCA has been the target of much debate: civil rights organizations such as the American Civil Liberties Union and internet communities such as Slashdot have vehemently attacked the DMCA as an unconstitutional document limiting fair use, while content providers (software companies, movie studios, etc.) and industry oversight organizations such as the RIAA and the MPAA view the DMCA as an absolute necessity to ensure their long-term profitability. We will present an overview of several common content distribution technologies that are currently at the center of the debate surrounding the DMCA (MP3, SDMI, and DVD), an analysis of their relative benefits or problems, a summary of the many arguments surrounding each technology, and an analysis of the changes that the DMCA has caused in regards to the many lawsuits currently in process. Our primary question for this site is whether or not basing laws on technology (such as is the case with the DMCA) is an ethical thing to do.