When an application is submitted to Amazon it is wrapped with additional code that enables the app to communicate with the Amazon Appstore client to collect analytics, evaluate and enforce our program policies, share aggregated information with you and others regarding the program, and for other purposes.
Amazon also removes the signature you used to sign your app and re-signs it with an Amazon signature that is unique to you, does not change, and is the same for all apps in your account.
Amazon signature hashes for your account can be found by selecting any application from the developer console and navigating to the APK Files tab. In the Appstore Certificate Hashes section both SHA-1 and MD5 hashes can be found.
Keywords: hash key, Facebook hash, app signing, app signature, app key