Thin vs. fat box entries draft

A Condensation box entry is a hash that points to an envelope.

In theory, boxes could store envelopes (fat entries) instead of hashes pointing to envelopes (thin entries). This, however, would have the following disadvantages:

• Envelopes are typically between 1 and 20 KiB in size. Storing this amount of data is significantly more complex as compared to storing a (fixed-size) 32-byte hash.
• A list request with a few hundred entries would amount to several MiB of data. Hence, a more complex box listing function (e.g. partial enumeration) would be necessary.

Thin entries therefore simplify the store design. Since envelopes are immutable, they can be treated as regular objects.