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    I know that it's slightly off topic but, really, it all comes back to BTC in the end anyway.
    Alexei Zamyatin

    Hi. Is anyone here, who can explain what exactly is happening in the m_saveAncestors and priv_fastGetBlockHash__ functions in btcChain.se? I understand the idea of the indexing of block ancestors but I'm concerned about the exact details of the implementation.
    Specifically, this code block in m_saveAncestors

               with $i = 1:
                    while $i < NUM_ANCESTOR_DEPTHS:
                        with $depth = m_getAncDepth($i):
                            if m_getHeight($blockHash) % $depth == 1:
                                m_mwrite32(ref($ancWord) + 4*$i, $prevIbIndex)
                                m_mwrite32(ref($ancWord) + 4*$i, m_getAncestor($hashPrevBlock, $i))
                            $i += 1

    Also, could it be, that priv_fastGetBlockHash__ fails if the requested block has more than 78125 confirmations? I may be wrong, but it seems to me that the following check will fail in this case:
    (excerpt from priv_fastGetBlockHash__):

        blockHash = self.heaviestBlock
        anc_index = NUM_ANCESTOR_DEPTHS - 1 <-- this is equal to 7
        while m_getHeight(blockHash) > blockHeight:
            while m_getHeight(blockHash) - blockHeight < m_getAncDepth(anc_index) && anc_index > 0:
                anc_index -= 1
            blockHash = self.internalBlock[m_getAncestor(blockHash, anc_index)]

    Note: m_getAncDepth(7) returns 78125


    Nekonium, Deft, MMO, BWS, INDI Fan
    hey guys.. i am admin to a discord with some hundersd coin programmmers and bitcoin related stuff. I would hope to win some more developers for our open community with a lot of job posting: And dont ban me:) https://discord.gg/K6q3j2U
    Can someone help me
    Arber Avdullahu
    Is the chat acitve?
    Nick Savers
    @arberiii what is it that you are looking for?
    Arber Avdullahu
    @nicksavers I want to find the gas cost for running a method of a contract, more specifically of Verify Tx on BTC Relay contract. How can I find it?
    Nick Savers
    @arberiii This is a guide you can use for most methods https://medium.com/@blockchain101/estimating-gas-in-ethereum-b89597748c3f
    Arber Avdullahu
    @nicksavers thanks :D
    Arber Avdullahu
    can I find some white paper or a detailed explanation on how BTCRelay works?
    Adam Skrodzki
    Hi is it online anywhere on ethereum ?
    Alexei Zamyatin

    Hi all. We've done (and are still doing) some PoC work on new BTC Relay designs (Solidity and Rust) and have used the "deprecated" BTC Relay implementation (Serpent) for some experiments.

    You can find some info on how chain relays (BTC Relay incl.) work in this paper: https://eprint.iacr.org/2018/643.pdf (Sections V.B and Appendix D) or here (more high level. Note: the code in this repo is not up to date I think): https://github.com/crossclaim/btcrelay-sol

    BTC relay itself is live on Ethereum, but it has not been used for ages. Also not sure if it can still be used.

    If you want some more theoretical background on different cross-chain verification techniques, read up here: https://eprint.iacr.org/2019/1128.pdf (Section 5)

    Hi namsthe,

    I want to develop Blockchain Dapp to for University purpose to store students certificate and marks list of graduate students in blockchain . So any company can verify their employees certificate verification from Blockchain instead of enquiring to colleges. This is my idea. Kindly suggest me tips and possible solutions. Whether shall I proceed with public or private Blockchain, which platform suitable, etc. Thank you.

    How closely is this related to the Kyber design?
    Gabriel Hayes
    Is it possible to create an application that provides a realtime service and also uses clients as miners for a mining pool? And if so, are there legal implications? i.e. most games require GPU, and offer multiplayer. It seems like all of the pieces are there to create a mining pool considering I would control the distro of software
    Hi ravachol, kyber design is it solution to my question asked yesterday.
    Hey guys how can i hack btc
    Please I need someone to help hack this address 0x131A99859a8bfa3251D899F0675607766736FFaE
    It's an ethereum wallet
    i write ecc decrypt use solidty, when i run decrypt function in remix,i can get the right result.when i deploy the contract to the geth and call function,i get the follow error:Error: invalid argument 0: json: cannot unmarshal hex string of odd length into Go struct field CallArgs.data of type hexutil.Bytes
    how can i solve this problem? plz, its import to me!