Hi,

I'm reading https://github.com/ethereum/wiki/wiki/Web3-Secret-Storage-Definition and am wondering about the (security) design decisions for the mac storage, specifically:

• Why is the ciphertext concatenated to the decrypted key, instead of just using the decryption key?
• Why is the 2nd 16 leftmost bytes used from the decryption key as input to the hash, instead of the full key?

Perhaps this is common knowledge and therefore ignorance on my part, but I guess it would be nice if it's documented somewhere too.

Regards,

-Freek