Beam Unique Features - Reading Assignment

Visit this exhaustive article on MimbleWimble. While you’re here, bookmark this site because it’s an amazing reference on all things blockchain privacy. When you’ve done that, read the section titled ‘BEAM Unique Features’, answer the questions and post your answers below:

  1. GRIN uses a timelock. What additional functionality does BEAM add to this timelock?
  2. BEAM proposes to improve scalability by letting users recycle transaction kernels. How will they encourage users to use this feature?
  3. In a GRIN transaction, both parties must be online at the same time. How does BEAM allow this to be done asynchronously?
  4. How does BEAM plan to support one-sided transactions?
  1. BEAM enables to specify an upper time limit on the timelock, which establishes a time limit after which the transaction will no longer be included in the block.
  2. By including a fee refund model for transactions based on such recycling process.
  3. Thanks to the implementation of the Secure Bulletin Board System (SBBS), which runs on BEAM full-nodes.
  4. Using “kernel fusion”, thanks to which a kernel can be used as reference to another one to make the transaction valid only if both are present.
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  1. Beam includes the ability to also specify an upper time limit, after which the transaction can no longer be included in a block. This feature means that a party can be sure that if a transaction is not included in a block on the main blockchain after a certain time, it will never appear.

  2. BEAM has proposed a scheme to reuse these transaction kernels to validate subsequent transactions. In order to consume the existing kernels without compromising the transaction irreversibility principle, BEAM proposes that a multiplier be applied to an old kernel by the same user who has visibility of the old kernel, and that this be used in a new transaction. In order to incentivize transactions to be built in this way, BEAM includes a fee refund model for these types of transactions.

  3. When constructing a valid Mimblewimble transaction, the parties involved need to collaborate in order to choose blinding factors that balance. This interactive negotiation requires a number of steps and it implies that the parties need to be in communication to finalize the transaction. Grin facilitates this process by the two parties connecting directly to one another using a socket-based channel for a “real-time” session. This means that both parties need to be online simultaneously. BEAM has implemented a Secure Bulletin Board System (SBBS) that is run on BEAM full-nodes to allow for asynchronous negotiation of transactions.

  4. BEAM are planning to support one-sided transactions where the payee in a transaction who expects to be paid a certain amount can construct their half of the transaction and send this half-constructed transaction to the payer. The payer can then finish constructing the transaction and publish it to the blockchain. Under the normal Mimblewimble system this is not possible, because it would involve revealing your blinding factor to the counterparty. BEAM solves this problem by using a process it calls kernel fusion , whereby a kernel can include a reference to another kernel so that it is only valid if both kernels are present in the transaction. In this way, the payee can build their half of the transaction with a secret blinding factor and a kernel that compensates for their blinding factor, which must be included when the payer completes the transaction

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• GRIN uses a timelock. What additional functionality does BEAM add to this timelock?

BEAM includes the ability to also specify an upper time limit, after which the transaction can no longer be included in a block.

• BEAM proposes to improve scalability by letting users recycle transaction kernels. How will they encourage users to use this feature?

BEAM includes a fee refund model for these types of transactions.

• In a GRIN transaction, both parties must be online at the same time. How does BEAM allow this to be done asynchronously?

BEAM has implemented a Secure Bulletin Board System (SBBS) that is run on BEAM full-nodes to allow for asynchronous negotiation of transactions.
• How does BEAM plan to support one-sided transactions?

Kernel Fusion, whereby a kernel can include a reference to another kernel so that it is only valid if both kernels are present in the transaction.

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  1. BEAM includes the ability to also specify an upper time limit, after which the transaction can no longer be included in a block.
  2. BEAM includes a fee refund model for these types of transactions. This feature will not be part of the initial release.
  3. BEAM has implemented a Secure Bulletin Board System (SBBS) that is run on BEAM full-nodes to allow for asynchronous negotiation of transactions.
  4. The payee in a transaction who expects to be paid a certain amount can construct their half of the transaction and send this half-constructed transaction to the payer. The payer can then finish constructing the transaction and publish it to the blockchain.
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  1. BEAM includes the ability to also specify an upper time limit, after which the transaction can no longer be included in a block.
  2. With a prospective fee refund model.
  3. Through the set up of the Secure Bulletin Board System (SBBS) which runs on BEAM full-nodes.
  4. With kernel fusion. Through this a kernel can be used as a reference to another kernel to make the transaction valid only if both are present.
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  1. BEAM - Timelocks with a minimum and maximum threshold. The maximum threshold means that if a tx is not included in the blockchain until this max=timeinstant the tx will never be included.
  2. “In order to incentivize transactions to be built in this way, BEAM includes a fee refund model for these types of transactions.”
  3. “BEAM has implemented a Secure Bulletin Board System (SBBS) that is run on BEAM full-nodes to allow for asynchronous negotiation of transactions”
  4. “BEAM solves this problem by using a process it calls kernel fusion , whereby a kernel can include a reference to another kernel so that it is only valid if both kernels are present in the transaction. In this way, the payee can build their half of the transaction with a secret blinding factor and a kernel that compensates for their blinding factor, which must be included when the payer completes the transaction”
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  1. Beam includes the ability to specify an upper time limit, after which the transaction can no longer be included in a block.
  2. To include a fee refund model for these types of transactions.
  3. It has implemented a Secure Bulletin Board System (SBBS) that is run on BEAM full-nodes to allow for asynchronous negotiation of transactions.
  4. By applying "kernel fusion” which able kernel to be used as reference to another one to make the transaction valid only if both are present.
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1-BEAM supports the traditional timelock feature but includes the ability to also specify an upper time limit after which the transaction can no longer be included in a block.

2- BEAM has proposed a scheme to reuse these transaction kernels to validate subsequent transactions. In order to consume the existing kernels without compromising the transaction irreversibility principle, BEAM proposes that a multiplier be applied to an old kernel by the same user who has visibility of the old kernel, and that this be used in a new transaction. In order to incentivize transactions to be built in this way, BEAM includes a fee refund model for these types of transactions.

3-BEAM has implemented a Secure Bulletin Board System (SBBS) that is run on BEAM full-nodes to allow for asynchronous negotiation of transactions.

4-BEAM also plans to support one-sided transactions where the payee in a transaction who expects to be paid a certain amount can construct their half of the transaction and send this half-constructed transaction to the payer. The payer can then finish constructing the transaction and publish it to the blockchain. Under the normal Mimblewimble system this is not possible, because it would involve revealing your blinding factor to the counterparty.

1 Like
  1. GRIN uses a timelock. What additional functionality does BEAM add to this timelock?
    BEAM includes the ability to also specify an upper time limit, after which the transaction can no longer be included in a block. This feature means that a party can be sure that if a transaction is not included in a block on the main blockchain after a certain time, it will never appear.

  2. BEAM proposes to improve scalability by letting users recycle transaction kernels. How will they encourage users to use this feature?
    Beam incentivises this with a fee refund model.

  3. In a GRIN transaction, both parties must be online at the same time. How does BEAM allow this to be done asynchronously?
    BEAM has implemented a Secure Bulletin Board System (SBBS) which is run on BEAM full nodes to allow for asynchronous negotation of transactions.

  4. How does BEAM plan to support one-sided transactions?
    With a process called kernel fusion, whereby a kernel can include a reference to another kernel, so that it is only valid when both a presented in s transaction. The payee can build half to the transaction with a kernel which compensates the blinding factor (without giving away the blinding factor) which must be included when the payer completes a transaction.

1 Like
  • GRIN uses a timelock. What additional functionality does BEAM add to this timelock?
    • BEAM also supports the traditional timelock feature, but includes the ability to also specify an upper time limit, after which the transaction can no longer be included in a block. This feature means that a party can be sure that if a transaction is not included in a block on the main blockchain after a certain time, it will never appear.
  • BEAM proposes to improve scalability by letting users recycle transaction kernels. How will they encourage users to use this feature?
    • With a fee refund model exclusively for this transaction type.
  • In a GRIN transaction, both parties must be online at the same time. How does BEAM allow this to be done asynchronously?
    • BEAM has implemented a Secure Bulletin Board System (SBBS) that is run on BEAM full-nodes to allow for asynchronous negotiation of transactions
  • How does BEAM plan to support one-sided transactions?
    • by using a process it calls kernel fusion, whereby a kernel can include a reference to another kernel so that it is only valid if both kernels are present in the transaction. In this way, the payee can build their half of the transaction with a secret blinding factor and a kernel that compensates for their blinding factor, which must be included when the payer completes the transaction
1 Like
GRIN uses a timelock. What additional functionality does BEAM add to this timelock?

An extension to timelocks which sets the maximum period a UTXO can be spent within. This is opposite of vanilla timelocks which define the minimum time period after which it can be spent.

BEAM proposes to improve scalability by letting users recycle transaction kernels. How will they encourage users to use this feature?

By offering a fee refund for those who use it.

In a GRIN transaction, both parties must be online at the same time. How does BEAM allow this to be done asynchronously? How does BEAM plan to support one-sided transactions?

Using kernal fusion allows the kernals to be constructed separately without revealing the blinding factor. This allows one party to initiate the transaction by constructing their half without direct interaction. The half finished transaction is then sent to the other party through the secure BBS where it waits for them to retrieve it, complete their half, and broadcast the transaction.

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  • GRIN uses a timelock. What additional functionality does BEAM add to this timelock?
    Incubation period on a UTXO, which limits its ability to be spent to a specific number of blocks after its creation .

  • BEAM proposes to improve scalability by letting users recycle transaction kernels. How will they encourage users to use this feature?
    In order to incentivize transactions to be built in this way, BEAM includes a fee refund model for these types of transactions.

  • In a GRIN transaction, both parties must be online at the same time. How does BEAM allow this to be done asynchronously?
    BEAM has implemented a Secure Bulletin Board System (SBBS) that is run on BEAM full-nodes to allow for asynchronous negotiation of transactions.

  • How does BEAM plan to support one-sided transactions?
    BEAM solves this problem by using a process it calls kernel fusion , whereby a kernel can include a reference to another kernel so that it is only valid if both kernels are present in the transaction. In this way, the payee can build their half of the transaction with a secret blinding factor and a kernel that compensates for their blinding factor, which must be included when the payer completes the transaction.

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1. GRIN uses a timelock. What additional functionality does BEAM add to this timelock?
BEAM adds a minimum and maximum threshold for timelocks.

2. BEAM proposes to improve scalability by letting users recycle transaction kernels. How will they encourage users to use this feature?
BEAM will encourage users to use recycled transaction kernels by including a fee refund model with these transactions.

3. In a GRIN transaction, both parties must be online at the same time. How does BEAM allow this to be done asynchronously?
BEAM allows asynchronous transactions by its implementation of the Secure Bulletin Board System that runs on full nodes.

4. How does BEAM plan to support one-sided transactions?
BEAM plans to allow the expected recipient to write their partial signature (of the whole signature within a tx) while awaiting for the payer to sign through a process called kernel fusion. In kernel fusion, the payee includes a reference to another kernel; in which case, the transaction will only be valid if the intended payer’s kernel is also included in the transaction.

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  • GRIN uses a timelock. What additional functionality does BEAM add to this timelock?
    Includes the ability to also specify an upper time limit, after which the transaction can no longer be included in a block.

  • BEAM proposes to improve scalability by letting users recycle transaction kernels. How will they encourage users to use this feature?
    Including a fee refund model for transactions that reuse old kernels.

  • In a GRIN transaction, both parties must be online at the same time. How does BEAM allow this to be done asynchronously?
    Implementing a system that runs on BEAM full-nodes to allow for asynchronous negotiation of transactions.

  • How does BEAM plan to support one-sided transactions?
    By using a process it calls kernel fusion , whereby a kernel can include a reference to another kernel so that it is only valid if both kernels are present in the transaction…

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  1. beam also allows for a upper limit, in time. meaning after this upper limit it is no longer possible for a transaction to be included in a block.
  2. they will encourage users to use this feature by allowing a refund of fees
    3.Beam as implemented a SBBS secure bulletin board system that is run on beam full nodes to allow for asychronous transactions. This means with Beam (but not with grin) that users don’t need to be online at the same time
    4.by using kernel fusion. a payee constructs his/her side of transaction and includes a reference in the kernel to another transaction, to be made by the payer. the payment is only valid if both kernels are in the transaction
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  1. Beam adds an upper bound so not only can the transaction not be spent before a certain time, it also will expire if it doesn’t get into a block before a certain time.

  2. By using a “fee refund” model for transactions using this feature.

  3. By using a store and forward network that operates similar to the old bulletin board systems of the 90s while being cryptographically authenticated.

  4. By allowing the payee to construct his half of the transaction and send it to the payer where they can finish constructing the transaction before publishing it to the blockchain.

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Q1: Beam allows you to add a a time limit on the time lock, meaning if a TX passes the time limit it will never go on the blockchain.

Q2: A fee refund model to incentivize use.

Q3: A Secure Bullet Board System running on BEAM full nodes.

Q4: Kernel Fusion, a kernel references another kernel to validate the TX

1 Like
  1. BEAM also supports the traditional timelock feature, but includes the ability to also specify an upper time limit, after which the transaction can no longer be included in a block

  2. In order to incentivize transactions to be built in this way, BEAM includes a fee refund model for these types of transactions. This feature will not be part of the initial release.

  3. BEAM has implemented a Secure Bulletin Board System (SBBS) that is run on BEAM full-nodes to allow for asynchronous negotiation of transactions

  4. BEAM also plans to support one-sided transactions where the payee in a transaction who expects to be paid a certain amount can construct their half of the transaction and send this half-constructed transaction to the payer. The payer can then finish constructing the transaction and publish it to the blockchain.

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  1. Setting a maximum time before which block the transaction needs to be included.
  2. Fee refund
  3. With a Secured Bulletin Board System on BEAM servers
  4. kernel fusion , whereby a kernel can include a reference to another kernel so that it is only valid if both kernels are present in the transaction. The sender can include a secret blinding factor and a compensating kernel for their half of the transaction.
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