Once in a while I will browse through IACR papers and read through interesting ones. Today I've encoutered this

https://eprint.iacr.org/2018/417.pdf Okamoto Beats Schnorr: On the Provable Security of Multi-Signatures

The authors claim they found a hole in security proof of MuSig:

Our first result essentially shows that the CoSi and MuSig schemes cannot be proved secure. (This obviously contradicts the security proof of MuSig [21], but we point out that the proof is flawed.) More precisely, we prove that if the OMDL problem is hard, then there cannot exist an algebraic black-box reduction that proves CoSi or MuSig secure under the DL or OMDL assumption.

I'm reading through it but it goes over my head. Anyone more knowledgeable care to comment on the MuSig security proof flaw?

Osnivanje Bitcoin udruge spominje se već neko vrijeme, ali prošli tjedan nas je nekoliko odlučilo poduzeti nešto po tom pitanju. Organiziramo meetup idući četvrtak (16.6) u Zagrebu u klubu MaMa (Preradovićeva 18) s početkom u 19:30 gdje ćemo raspravljati o sljedećim temama:

1. Ime Udruge

2. Područje djelovanja (Bitcoin, virtualne valute, blok-lanac tehnologije, digital assets...)

3. Organizacijska struktura (centralizirana / decentralizirana)

4. Načini odlučivanja i komunikacijski kanali

5. Hoće li se i kakvim gospodarskim djelatnostima baviti udruga?

Budući da će udruga biti na razini države, odlučio sam vas obavijestiti ovim putem da nam se na meetupu pridruži tko može. Tko ne može, a zainteresiran je, slobodno neka ovdje stavlja prijedloge, komentare, mišljenja, kritike itd., jer će se uzeti u obzir. Stranica meetupa je ovdje http://www.meetup.com/Bitcoin-Group-Zagreb/events/231768956/ pa i tamo možete komentirati. Za ubuduće ćemo otvoriti komunikacijski kanal (npr. slack.com) kako bi nas što više moglo sudjelovati u ovome. Nadam se da će te se uključiti.

To redeem a particular transaction output, the spender needs to provide transaction signature and his pubkey:

<sig><pubkey> DUP HASH160 <address> EQUALVERIFY CHECKSIG

The provided pubkey will get (duplicated and) hashed HASH160(SHA56(pubkey)) and compared to the provided address. But how can this pubkey hash be equal to the address when the address also has checksum and network prefix? Does that mean the extra data gets removed from the script at some point? Also, is there any reason why provided address is in hex format instead of base58?

After updating OpenSUSE 13.2 my MB is crashing every time I enter the password. I found a topic about this on github https://github.com/jim618/multibit/issues/325 I tried the soulution proposed by drizzt: zip -d "multibit-exe.jar" lib/x86_64/{freebsd,linux}/libscrypt.so
but I get:

zip warning: name not matched: lib/x86_64/freebsd/libscrypt.so
zip warning: name not matched: lib/x86_64/linux/libscrypt.so

Does anyone have similar problem and knows a solution?

Bok svima! Mislio sam da bi bilo dobro da imamo svoju temu za meetupe u Hrvatskoj jer ne znam koliko vas zna za http://www.meetup.com/Bitcoin-Group-Zagreb/ Sedmi zagrebački meetup je sutra, 23. 12., u kafiću History u Village dijelu gdje je BTM. Počinjemo se okupljati u 18 sati. Link s detaljima je ovdje http://www.meetup.com/Bitcoin-Group-Zagreb/events/219315199/