Lets say alice is trying to send data to bob , should alice first hash the data and then encrpt or vice versa

  • 2
    $\begingroup$ Note that if you'd use an AEAD scheme then the decision has been made for you. Note that you should also protect the IV and possibly other information that cannot / doesn't need to be encrypted (the IV is protected automatically in AEAD schemes). $\endgroup$ – Maarten Bodewes Jul 31 '19 at 13:34