Even just replacing the single icon won't let us to install the apk normally (if we have the "true official untouched" system core including phonesky/market) if we don't "really sign it". I believe this because I've met the same case as AryanAkanskh. Except we push the "modified" apk without signing MAY will work.
The META-INF or "APK SIGN" contain hash code (md5 or whatever they called it) for every single file inside the apk. I assume the "sign" is the first security check in android system when we want to install (let's say copy-paste from the original source to "userdata/app" partition) any apk. That's why when we "manually install" it (push to userdata or system) will work even without signing, as long as the AndroidManifest.xml wasn't modified.
But, that's all my opinion, just assuming. So, please correct me if any of my statement is wrong. :highfive:
The META-INF or "APK SIGN" contain hash code (md5 or whatever they called it) for every single file inside the apk. I assume the "sign" is the first security check in android system when we want to install (let's say copy-paste from the original source to "userdata/app" partition) any apk. That's why when we "manually install" it (push to userdata or system) will work even without signing, as long as the AndroidManifest.xml wasn't modified.
But, that's all my opinion, just assuming. So, please correct me if any of my statement is wrong. :highfive: