wallet.dat size in Bitcoin Core Just created a new wallet using Bitcoin Core v0.15.1 (Windows x64), encrypted it with a password, and created one receiving address. The size of this wallet is 1 Mb.

In comparison, my old wallet, with about a dozen receiving addresses and transactions, encrypted using the password of the exact same length, is only 100 Kb.

I thought the 1 Mb is too large and suspicious. What could be the reason for this size?
The default size of the keypool was raised from 100 keys to 2x 1000 keys.

This was done in order to reduce the cases where recovery of a backup needs to decrypt the wallet to generate further keys.