Securely exchanging information during application startup

A computer program product comprising a computer readable storage medium having program instructions embodied therewith, the program instructions executable by a processor to cause the processor to perform a method comprising:

• storing, in a first configuration file for an application, an encryption algorithm, contact information for two or more remote devices, an encryption key, a key derivation function, and initialization information for the application, the initialization information including parameters and initial settings that enable the application to transmit SMS text messages;
• encrypting, using the encryption key and the encryption algorithm, application startup data for the application using a (t,n)-threshold scheme, wherein the application startup data includes initial settings, parameters, functions, and passwords that are necessary for the application to execute and access one or more databases;
• storing the encrypted application startup data for the application in a second configuration file, the second configuration file being distinct from the first configuration file;
• receiving a request to execute the application;
• identifying, using the first configuration file and in response to receiving the request to execute the application, a first remote device and a second remote device, the first remote device belonging to a first group and the second remote device belonging to a second group, each group having a distinct passphrase, wherein decrypting the application startup data requires a passphrase from a remote device in each group;
• sending a first request for a first passphrase to the first remote device using a first out-of-band message;
• sending a second request for a second passphrase to the second remote device using a second out-of-band message;
• receiving a first response having the first passphrase from the first remote device, the first response being a third out-of-band message;
• receiving a second response having the second passphrase from the second remote device, the second response being a fourth out-of-band message,
• wherein the first out-of-band message, the second out-of-band message, the third out out-of-band message, and the fourth out-of-band message use the same out-of-band communication channel, the first, second, third, and fourth out-of-band messages being SMS text messages;
• determining an order in which the first and second passphrases are to be combined;
• concatenating the first passphrase and the second passphrase according to the determined order to generate a concatenated passphrase;
• generating, using the key derivation function and the concatenated passphrase, a decryption key;
• decrypting, using the generated decryption key and the encryption algorithm, the application startup data stored in the second configuration file for the application;
• and
• executing the application using the decrypted application startup data.