Android Question signature for file exchange


Licensed User
HI, All

How any sign mechanism can be implemented for file exchange ?
Say, docs from the head department is received, read and signed in Android app. And the head dept can check that who signed.
Also, the signature of the head dept can be verified by the doc receiver in the same Android app.
It's like in Adobe Acrobat signature function.
It's not encription of the content, just sign & verification.

Any ideas ?


Licensed User
1) Get file to be signed
2) Using your SimplePGP to prepare PublicKey & PrivateKey
3) Get some hash of the file
4) Encrypt the hash by the PrivateKey and save to the signature file near the source file
5) Send the file, the signature file and the PublicKey file (combined any how) to the other side
6) Other side unpacks files, checks the signature and compares both hashs (received and just computed), and allows to read the main file, if equal