Appendable Data (AD) entries/pointers

  1. Does it cost anything (SafeCoins) to add an entry into an existing AD?
  2. Can I add invalid pointers? I mean, a pointer to a non-existent structure. I’m thinking to encode data and pretend they are pointers.
  3. Can I have duplicated pointers on a list?
  4. RFC says AD max size is 100KiB. Does it mean that I can have 100KiB of data, plus 100KiB in priv entries, plus 100KiB in pub entries, i.e. 300KiB in total?
  5. Best case scenario we can store about 1k pointers (AD max size = 100k, 100B each priv/pub entry). Is there any recommendation/standard/best practices to store more items than this?
  6. Sorting: are these entries chronologically sorted?
  7. Delete: what if an attacker appends a lot of junk entries in my AD, blocking it for new, legitimate, writings? Can I use the “delete” method to release space again? Or will “delete” just move the entries from a list to another, and thus my AD will be forever blocked for new writings?


For information: Appendable Data (and Mutable Data) have been superceded by Mutable Data which is not yet documented except in code and any test apps.

Your questions will I think remain valid. Just letting you know!