Chapter 4 assessment 3

• What is the benefit of P2MSH over P2MS?

  • The number of signatures needed can be adjusted after the output is created, making the solution more flexible

  • The public keys of the participants are not revealed until the output is spent, improving privacy <-

  • The signatures generated are more secure

  • The public keys stay secret forever allowing for anonymous transactions

• What specific actions did nodes need to take to enable P2MSH scripts to be supported?

  • They needed to create special templates to detect P2MSH transactions and check the solutions

  • They needed to publish wallet guidelines so that developers could correctly implement P2MSH

  • They needed to create a peer-to-peer protocol for wallets to use to correctly distribute the partial solutions for signing

  • They didn't need to do anything <-

• What does the user's wallet need to do in order to create and then solve an R-Puzzle?

  • Generate a secret r-value for use in the scriptSig so that it can be hashed when building the solution

  • Choose a non-random k-value and use the corresponding r value to generate the script Sig, and to generate the subsequent signature that spends the UTXO <-

  • Pre-calculate the signature before the transaction output is created and hold it in the user's wallet

  • Extract r from the user's public key when the signature is being created and submit it as a separate part of the solution

• Which of the following lists correctly defines the elements of a signature encoded for use in Bitcoin?

  • <-

    1. 0x30 - DER signature header

    2. Length of signature (excluding SIGHASH)

    3. 0x02 - Integer value header

    4. Length of r

    5. r as a big-endian integer

    6. 0x02 - Integer value header

    7. Length of s

    8. s as a big-endian integer

    9. 1 byte sighash flag

  1. 0x30 - DER signature header 2. Length of signature (including SIGHASH) 3. 0x02 - Integer value header 4. Length of r 5. r as a big-endian integer 6. 0x02 - Integer value header 7. Length of s 8. s as a big-endian integer 9. 1 byte sighash flag * [ ] 1. 0x30 - DER signature header 2. Length of signature (excluding SIGHASH) 3. 0x02 - Integer value header 4. Length of r 5. r as a little-endian integer 6. 0x02 - Integer value header 7. Length of s 8. s as a little-endian integer 9. 1 byte sighash flag * [ ] 1. 0x30 - DER signature header 2. Length of signature (including SIGHASH) 3. 0x02 - Integer value header 4. Length of r 5. r as a little-endian integer 6. 0x02 - Integer value header 7. Length of s 8. s as a little-endian integer 9. 1 byte sighash flag