How I do to store a secret key in a android device with the only possibility to use the key, not retrieve it. Eg: I import a private/generate a RSA keypair or a symmetric key from a application to this "secure storage". Now, NOBODY should be able to retrieve the secret key, not even the original application. (The non-secret part of key - the public key of a RSA keypair - but no part of a symmetric key - should still be retrieveable, especially if the key is generated in the secure storage)
The keystore should now act as a black box, providing a input for encrypted data and a output for decrypted data, eg I feed my encrypted values that I want to decrypt, and gets the decrypted values back.
Its a big plus if this is implemented in a hardware security chip in the android device, like a smart card chip, which is tamper-resistant, which would also keep the keys secure even if the device is rooted & cloned.
Any ideas which android mobile phones, that has such a tamper-resistant chip? Any ideas on how to use such a storage?
Found a similiar question: Android Secure Storage but this does not answer my questions.