Turbine creates more resigned shreds then necessary

[alexpyattaev]

Problem

Turbine requires the last 64 shreds (1 FEC set) of a block to be resigned for security reasons. However, current implementation in

agave/ledger/src/shred/merkle.rs

Line 1040 in 021237a

let resigned = chained && is_last_in_slot;

will create an entire batch of resigned shreds (which may contain >64 shreds).

• This creates additional sigverify load that is not justified by security requirements if the last entry batch is larger than 1 FEC set.
• Resigned shreds have slightly less data capacity and as such may increase the number of packets needed.

Proposed Solution

• Change the logic in fn make_shreds_from_data to create only the very last FEC set with resigned shreds, while keeping all others as full-size data shreds.

[iTranscend]

Can I take this?

[alexpyattaev]

Of course!

[RaghavenderSingh]

Hey can i work on this??
@alexpyattaev