Genesis support and eclipse resistance

[njd42]

Need to set out the arguments that support the thesis that the appropriate preconditions are understood and in place.

In particular that the key assumption of Genesis, namely that they have access to a honest hot peer during Genesis process is true with high probability.

Depends on:

• Genesis Design - currently on private fork

Required for:

• Highl level Peer Sharing Implementation Plan #3940
• Peer Sharing & Eclipse Evasion Design #3862
• Peer Sharing and Eclipse Evasion Design #3884

[njd42]

Outline of activity:

• need a stronger reasoned argument for the effects of
  • initial choice of ledger peer set
  • the consequence of resampling from that set (either due to churn or loss and replacement of peer)

Capture potential mitigations for the (extremely small) residual risks

• document the nature of the attacks (this may not done in a public forum)
• suggested user oriented mitigations (perhaps arranged by "size" ie individuals and corporate