In my humble opinion, this mempool attacks are done by miners, this happened also during the China Mining Shutdown (first half of 2021) or by people who want high fees and impede mass adoption.

Supose 1 block = 1Mb data @ 1 sat/byte = 10 485 76 sat = 0,01 BTC (tx fee) / block

With sufficient spam blocks (50K) the average price/sat is then increase 10x (in fact much higher), for each block you mined, you get back the cost of 10 blocks spammed.

In case the attack is against the network itself the cost to have 50Mb mempool = 50 blocks is 50 x 0,01 = 0.5 BTC = 12500 USD

Any actor can invest 10k or 20K to make BTC transacions fees high for weeks

I think this is a real problem for BTC is it ?

I use new RYO wallet for windows
I tried twice (resync full block chain two times)

I tried wallet sync in the three modes I always get the same error, in my case it was

sync message stays for long time in block 264787 then it goes for a second to block 265035 then it goes back again to block 264787

my wallet address is  RYoLse6w1UT63Eyiqdz8W2H2WVrAF8AHaTRbHBYcpPRicmE6da1zih2Dcm677aPmWBF9nejSjPTQgDX jwbN7Mgbhb7DGDWAkGCg


Should I understand that the full version 0.5.0.1 of RYO Wallet does not run properly?

Hello I think I know how to use 'Replace by fee', to accelerate a transaction increasing the fee. This option is already running in the GUI of Electrum as far as I know.

Now what about an option to modify a transaction (already sent to the memory pool and pending) sending a new one changing the outputs and increasing the fees so the original transaction is replaced by the newly crafted one, so the funds can go back to the wallet or just go to someone else.

Actually a new transaction with higger fee canot be crafted as funds are verified to be already spent (penfing).

This option could be the last line of defense for buggy transactions just sent to the Memory Pool.

Thank You.