I'm taking the course computer networks and we currently had our second lecture. We got the following question:
What are the differences between integrity and confidentiality of a message? Is confidentiality possible without integrity? What about integrity without confidentiality? Explain.
From what I understand the main difference between confidentiality and integrity is that "confidentiality" should prevent from spying on the message / intruders. And "integrity" is to ensure that the original message hasn't been altered in any way (modification/deletion/insertion).
What I'm unsure about: Does confidentiality mean that a possible interuder can't decode the ciphertext, or does this mean he can't even intercept the cipher?
To the two questions about the dependecies of integrity and confidentiality: At first I thought: If an intruder can't intercept the message (break confidentiality), there's no way he can alter the message in any way (break integrity). But the more I think about that, the less certain I become. Especially when I think about deletion of a message.
Thanks a lot in advance for clearing things up.
P.S: I hope "confidentiality" and "integrity" are the right terms in English. We learned "Vertraulichkeit" & "Integrität" in German.