Techniques for conducting secure online transactions using captcha images as watermarks are provided. Some techniques combine a trusted, secure device that utilizes a key to generate identifiers with a watermarked transaction verification request page to provide secure online transactions. The trusted,...http://www.google.de/patents/US20060287963?utm_source=gb-gplus-sharePatent US20060287963 - Secure online transactions using a captcha image as a watermark
