Module election

Functions for leader selection based on the DRB.

The algorithm we use is:

Initialization:

• obtain drb: [u8; 32] from the DRB calculation
• sort the stake table for a given epoch by xor(drb, public_key)
• generate a cdf of the cumulative stake using this newly-sorted table, along with a hash of the stake table entries

Selecting a leader:

• calculate the SHA512 hash of the drb_result, view_number and stake_table_hash
• find the first index in the cdf for which the remainder of this hash modulo the total_stake is strictly smaller than the cdf entry
• return the corresponding node as the leader for that view

Structs

RandomizedCommittee

Functions

cyclic_xor 🔒

Calculate xor(drb.cycle(), public_key), returning the result as a vector of bytes

generate_stake_cdf

Generate the stake table CDF, as well as a hash of the resulting stake table

select_randomized_leader

select the leader for a view