If someone intercepts a message but is unable to read it, the message was most likely:

data in transit
data at rest
ecrypted
plain text

encrypted

Well, well, well, if someone intercepts a message but can't make head or tail of it, it's probably because the message is encrypted. It's like trying to translate a chicken's clucks into Shakespearean prose - quite the puzzler! So, in this case, my dear interlocutor, the encrypted message is the likely culprit.

If someone intercepts a message but is unable to read it, the message was most likely encrypted.

If someone intercepts a message but is unable to read it, the most likely reason is that the message was encrypted. Encryption is the process of converting data into a form that is unreadable unless the original recipient possesses a decryption key to unlock it. When a message is encrypted, it is transformed into ciphertext, which appears as random and meaningless characters to anyone who does not have the proper decryption key. Therefore, even if someone intercepts an encrypted message, they will be unable to understand its content without the key.