No, it works completely offline without needing an internet connection.
You can use it with confidence for a few simple reasons. This is not the first app to require access permission to manage SMS messages. There are several apps that require this permission to manage SMS messages, although none of them have been designed to potentially increase the security of your conversations. The Google Play Store monitors these apps very closely and seriously and will not allow them to be published if they are found to be in violation of the slightest.
But for the convenience of users and the very technical aspect of this issue, we have disconnected the Internet access for this program and removed the access permission from it. So there is no way to transfer users’ personal data and leak it. More advanced users can check the accuracy of this issue by the package managers.
For details on this issue, we strongly recommend that you read the app’s Terms of Use and SMS Encryption Terms. But in general, if the use of encryption, and more specifically SMS encryption, does not conflict with your local and national laws, you are of legal age to use it, and you are not using it for illegal or dangerous purposes, you should have no problem using it, and it is only to increase your privacy in permissible circumstances.
E2EE, The app uses end-to-end encryption, double encryption for confidential messages, and the RSA cryptosystem for secure key exchange. and AES 192/256 for message transfer. (Depends on users’ subscription plan, AES-192 is used for regular users and AES-256 for Core-Pack subscribers.)
In addition to providing a secure connection, this application provides even greater security locally by using an encrypted database inside the phone device. It is almost impossible to hack this data and even the backup file without having the master password.
Yes, encrypted messages can be recovered by remembering your main password. But without it, nothing can be recovered. Restoring connection keys is only possible with a backup file. If you don’t have that backup, you will have to reconnect with your contacts and exchange keys again.
Yes, it allows extended SMS messages larger than the usual SMS limit. This is done by internal compression, which dramatically reduces the length of large messages instead of increasing the length of messages due to encryption, additional data transfer, and extensions. Due to the inherent nature of compression, this does not happen for very short messages, but the cost of sending those messages remains the same because the cost of sending usually depends on the number of messages. Short messages still do not exceed one message.
Yes, you can schedule SMS or delay sending to cancel before it is delivered. But there are always unpredictable system and external factors that may prevent such messages from being sent at the specified time or at all. For example, the device being turned off at the scheduled time. So we recommend not using this method to send essential messages.
Overall, Core-Pack is suitable for users who need more security due to their more sensitive conversations. This plan focuses more on security features and is suitable for businesses or individuals who need more privacy. The features of Shell-Pack are also automatically available to subscribers of this plan.
Yes, it can view and manage all previously unencrypted SMS messages if it has permission to access them. It can also open and view them if you have used the app before and remember your master password. You do not need a backup file to do this.
Naturally, standard libraries are used for user interface elements, general application elements, compression, and encryption. but for data transfer in the limited context of SMS, a completely unique protocol has been designed, the use of which is currently exclusive to this application and it’s developer. Other programs or applications are not allowed to copy or use it under any circumstances.
If you did not find an answer to your question in this section or have a specific question, you can ask it in the active question and answer section.