The apk must be signed with the same certificates as the previous version while uploading apk on market

Question

I have created an application and published on android market. now i want to publish its 2nd version. the few thing i want to make clear:

1. I have kept same package

Answer 1

Yes, You have to have the same keystore file which you have used to upload the 1st version of application on android market.

If you have lost this keystore file then you can't provide update to this application.

Just read this Publishing App on Market. The same problem i've also faced. So, i just change the package name and upload it into market with new keystore. So, keep the Keysotre file safely. See these existing questions which is related to your queries -

1. Android: I lost my android key store, what should I do?

2. I lost my .keystore file?