[bitcoin-dev] hashcash-newhash

2020-05-23 Thread Karl via bitcoin-dev
Hi, I'd like to revisit the discussion of the digest algorithm used in hashcash. I believe migrating to new hashing algorithms as a policy would significantly increase decentralization and hence security. I believe the impact on existing miners could be made pleasant by gradually moving the bloc

[bitcoin-dev] MIN_STANDARD_TX_NONWITNESS_SIZE and OP_RETURN

2020-05-23 Thread Thomas Voegtlin via bitcoin-dev
Hello list, I have been trying to CPFP a transaction using OP_RETURN, because the remaining output value would have been lower than the dust threshold. The scriptPubkey of the output was OP_RETURN + OP_0, and there was a single p2wsh input. The result is a 60 bytes transaction (without witness),

Re: [bitcoin-dev] MIN_STANDARD_TX_NONWITNESS_SIZE and OP_RETURN

2020-05-23 Thread Greg Sanders via bitcoin-dev
AFAIU the number was picked to protect against CVE-2017-12842 covertly. See: https://github.com/bitcoin/bitcoin/pull/16885 which updated the text to explicitly mention this fact. On Sat, May 23, 2020 at 11:20 AM Thomas Voegtlin via bitcoin-dev

Re: [bitcoin-dev] MIN_STANDARD_TX_NONWITNESS_SIZE and OP_RETURN

2020-05-23 Thread Greg Sanders via bitcoin-dev
So I think the question to ask would be "why can't we just make sure it's not 64?" On Sat, May 23, 2020 at 11:24 AM Greg Sanders wrote: > AFAIU the number was picked to protect against CVE-2017-12842 covertly. > See: https://github.com/bitcoin/bitcoin/pull/16885 >

Re: [bitcoin-dev] MIN_STANDARD_TX_NONWITNESS_SIZE and OP_RETURN

2020-05-23 Thread ZmnSCPxj via bitcoin-dev
Good morning Thomas, > So I think the question to ask would be "why can't we just make sure it's not > 64?" If we accept a 60-byte tx, then SHA-256 will pad it to 64 bytes, and it may still be possible to mount CVE-2017-12842 attack with 32-bits of work. Of course some other details will be cha

Re: [bitcoin-dev] hashcash-newhash

2020-05-23 Thread ZmnSCPxj via bitcoin-dev
Good morning Karl, > Hi, > > I'd like to revisit the discussion of the digest algorithm used in hashcash. > > I believe migrating to new hashing algorithms as a policy would significantly > increase decentralization and hence security. Why do you believe so? My understanding is that there are e