Older versions of iPhone OS aren't new enough to have modern certificate authorities trusted, meaning only sites using older certificate authorities are able to have a secure connection.

Here are links to modern Certificate Authorities that may not be trusted on older devices (some other complications may prevent sites using these certificates from working, those can not be fixed by these.)

"tass Upolnomochen Zayavit..." Seriya 2(1984) Official

Episode 2 of the Soviet spy thriller "TASS is Authorized to Declare..." (1984) shifts to the field, following KGB Colonel Slavin to Africa to investigate a mysterious letter while the hunt for the CIA mole "Trianon" intensifies in Moscow. Directed by Vladimir Fokin, the series highlights intellectual counter-intelligence and sets up a complex international plot aimed at defending a pro-Soviet government in Nagonia. View the episode on OK.RU .

ТАСС УПОЛНОМОЧЕН ЗАЯВИТЬ...(все серии подряд) шпионский "TASS upolnomochen zayavit..." Seriya 2(1984)