[erviins]

Is it possible to sign one midlet, for example using Verisign, java verified and thawte certificates and hope that at least one of thouse authorities root certificate will be intalled on phone?
Or in this case there should be 3 separate signed midlets?

[traud]

Does this help? However, why do you want to go for all three?

[erviins]

yes, thanks for link.
if Midlet is signed using more certificates, there is higher possibility that at least one root certificate will be installed on phone and phone would allow, for example, making socket connections.

[traud]

As you can see in that thread, having multiple certificates in one MIDlet might raise new problems! If you have Java Verified, you have done a lot already. If you have VeriSign, you have done a lot, too. I highly recommend to try and test before spending zillions of bugs. Avoid signing whenever possible, for example go for other socket ports.

If you go through a sales channel, they will tell which authority to use. If you do the sales yourself, either test, test and test or start with one certificate like VeriSign and then decide whether to go for thawte and/or Java Verified, too. However, your biggest problem are the operator branded versions. So, avoid signing if you can: All major players try to do that (Google Maps, Opera Mini, …).