This little tutorial is about signing and verifying data you send/receive between apps (= all "programs", even websites). You can use it in B4A without a change (I don't know how B4i works, but I assume there are similar libs).
You should know how RSA works. If not, take a Google search and you...
Hi, I have the following code
Dim su As StringUtils
Dim Bconv As ByteConverter
Dim ForeignPubKeyString As String
Dim ForeignPubKeyBytes(0) As Byte
Dim ForeignPrivKeyBytes(0) As Byte
Dim ForeignPrivKeyString As String