Which gives better deterministic encryption SIV or Plain ECB mode?

Question

Lets say , if we encrypt a plain text message $msg$ with key $key$ in below two ways. Which is the below would give better deterministic encryption and why ?

1. AES-ECB($key$ , $msg$)
2. SIV($key$, NIL , $msg$) where associated data is NIL.

I could not make out much from Rogaway and Shrimpton's paper on "Deterministic Authenticated Encryption" which introduces Synthentic IV (SIV) mode.

Edit: Here $msg$ is same as single block .

Answer 1

Both:

• Secure deterministic encryption for one-block messages.

ECB:

• No expansion for block-sized messages.
• Faster.

SIV:

• Authentication.
• Works for messages of any size.