Decryption Dictionaries

Note that the size of the table depends only on the number of different IV's you're likely to see.
In particular, it is independent of the size of the shared secret key.
It doesn't matter if you're using 40-bit keys or 104-bit keys (the two common key sizes)
If the cards that are being used have the IV-reset-to-0 property, then most IV's will be small, and the dictionary will be even smaller!