I downloaded and installed Opera Mini on my iPhone a few days ago. At a glance, it looked very impressive: tabs like in "real" browser, start page with convenient shortcut icons, and finally most important - double speed if you compare it to Safari. But what is a price of such performance, if any? After brief research I found out that there is a cost for increased speed: security. Opera improves the browsing speed by preloading the web pages to their servers, compressing and encoding them and then sending the compressed stream to the iPhone client which decompresses and decoding them in order to show to the user. As cellular communication is still a bottleneck, such approach dramatically improves the speed. However, when traffic is encrypted with SSL, it must be decrypted by the Opera server and then re-encrypted again in order to be compressed and encoded, which means that there is no true end-to-end encryption anymore, and if someone breaks into the Opera data center, the sensitive data will be compromised. On the other hand, since it always encrypts the traffic between the browser client application and the Opera software server, the regular website browsing is more secure than one performed by Safari! The bottom line: for maximum security, browse regular websites with Opera, but use Safari for https protected places, especially for financial and payment applications such as online banking and PayPal. Since most of financial institutions provide their own apps for iPhone, the Opera Mini browser for iPhone still has a good chance to compete with Safari.