codex-research/evaluations/ipfs.md

An evaluation of the IPFS paper
===============================

2021-01-07 Dagger Team

https://ipfs.io/ipfs/QmR7GSQM93Cx5eAg6a6yRzNde1FQv7uL6X1o4k7zrJa3LX/ipfs.draft3.pdf

Goal of this evaluation is to find things to adopt or avoid while designing
Dagger. It is not meant to be a criticism of IPFS.

#### Pros:

+ IPFS is designed by simplifying, evolving, and connecting proven techniques
  (§3)
+ Consists of a stack of separately described sub-protocols (§3)
+ Uses Coral DSHT to favor data that is nearby, reducing latency of lookup
  (§2.1.2)
+ Uses proof-of-work in S/Kademlia to discourage Sybil attacks (§2.1.3)
+ Favors self-describing values such as multihash (§3.1) and multiaddr (§3.2.1)
+ BitSwap protocol for exchanging blocks supports multiple strategies (§3.4.2),
  so it should be relatively easy to add a micropayment strategy.
+ Uses content addressing (§3.5)
+ The Merkle DAG is simple, yet allows constucting filesystems,
  key-value stores, databases, messaging system, etc.. (§3.5)

#### Cons:

- Kademlia prefers long-lived nodes (§2.1.1), which is not ideal for mobile
  enviroments (although it's unclear whether there are any better alternatives)
- The default BitSwap strategy falls just short of introducing a currency with
  micro payments, necessitating additional work for nodes to find blocks to 
  barter with (§3.4)
- Object pinning (§3.5.3) inevitably leads to centralized gateways to IPFS, such
  as Infura and Pinata
- IPFS uses variable size blocks instead of fixed-size chunks (§3.6), which
  might make it a bit harder to add incentives and pricing
- Supporting version control directly in IPFS feels like an unnecessary
  complication (§3.6.5)