The document discusses scalability issues facing Bitcoin and potential solutions. It notes that Bitcoin can currently only handle 7 transactions per second compared to Visa's 2000 transactions per second. One issue is that Bitcoin has a maximum block size of 1 megabyte, limiting it to around 2000 transactions per block. Solutions proposed include removing or increasing the block size limit, which would require a protocol update and risk blockchain forks. It also discusses optimizing initial blockchain synchronization by downloading only block headers, unspent transaction outputs (UTXOs), and a few hundred recent blocks from peers.

1. Scalability you said ?
BdxCoin #7

2. The prophecy
“Bitcoin will be able to scale to handle as
many transactions as the current payment
systems”
Is it the case today ?

3. Is it a real problem ?
Visa handles about 2000 Tx / s
Bitcoin can handle 7 Tx / s
NO BULLSHIT

4. Block size
Maximum block size : 1 MB
about 2000 transactions
Why ? Avoid DoS attacks

5. Block size evolution
Average block size 2010-now (source quandl.com)

6. Wat do ?
Remove block size limit ?
Increase block size like difficulty ?
-> Protocol update -> Blockchain fork

7. Blockchain size
Initial download size : 23+ GB and counting.
Is it really needed ?

8. Blockchain size

9. Blockchain size
What do we need ?
● UTXO : Unspent Transaction Output
● Validated by a hash in block headers
● A few hundred full blocks in case of a fork

10. Wat do ?
Initial download :
- Get longest chain headers from peers
- Get UTXO from a peer
- Check UTXO against blockchain
- Get a few hundred blocks
-> This needs a fork too.

11. Upcoming problems ?
CPU performance ?
-> new ECDSA lib to be rolled out
Storage ?
-> Moore law
We need more full nodes !

12. Thank you
Time for a glass of wine !
(or questions maybe ?)
BdxCoin.org
@bdxcoin
@dqms_output
@DjowIsGreat
@ChezWam
@tuxication