Most people non familiar with Bitcoin thinks that there its has not smart contracts capabilities, and that is incorrect, there are smart contract capabilities, and despite limited in comparison with other blockchain networks, those capabilities are evolving slowly but surely.

The support for smart contracts is done through its scripting language, Script, which allows developers to create complex conditions for transactions.

What can you do with Script?

1. time locks
2. multi-signature requirements
3. other custom logic

opcodes like OP_CHECKLOCKTIMEVERIFY (CLTV) and OP_CHECKSEQUENCEVERIFY (CSV) are used to build more sophisticated smart contracts, these opcodes enable features such as the Lightning Network, a key scaling solution for Bitcoin

back in 2021, the ***Taproot ***upgrade introduced Pay-to-Taproot (P2TR), in summary allows for more private and efficient smart contracts, in that soft fork more was added, in addition to Taproot, we got as well Schnorr signatures, which enables multiple signatures to be aggregated into a single signature, improving scalability and privacy and MAST (Merklized Abstract Syntax Trees) which reduces the size of complex smart contracts, making them more efficient, as an added value, this efficiency reduces the cost of transactions.

The ***Taproot ***upgrade has laid the foundation for the development of more sophisticated smart contracts on the Bitcoin network, and the use of covenants is an important part of this development.

What is Bitcoin Covenants?

It is a BIP (Bitcoin Improvement Proposal), BIP-347, assigned on April 24, 2024, which marks the first step towards reintroducing functionality removed from Bitcoin by its creator Satoshi Nakamoto in 2010. This proposal aims to bring smart contract functionality to Bitcoin as we see in other EVM networks.

The proposal’s developers authors names are Ethan Heilman and Armin Sabouri, now the community will debate its merits.

Here the link, in case you are curious:

https://github.com/bitcoin/bips/blob/master/bip-0347.mediawiki

It is worth to read the motivation section of the BIP, which reads:

“Bitcoin Tapscript lacks a general purpose way of combining objects on the stack, restricting the expressiveness and power of Tapscript. This prevents, among many other things, the ability to construct and evaluate merkle trees and other hashed data structures in Tapscript. OP_CAT, by adding a general purpose way to concatenate stack values, would overcome this limitation and greatly increase the functionality of Tapscript.

OP_CAT aims to expand the toolbox of the tapscript developer with a simple, modular, and useful opcode in the spirit of Unix. To demonstrate the usefulness of OP_CAT below we provide a non-exhaustive list of some use cases that OP_CAT would enable:

Bitstream, a protocol for the atomic swap (fair exchange) of bitcoins for decryption keys, that enables decentralized file hosting systems paid in Bitcoin. While such swaps are currently possible on Bitcoin without OP_CAT, they require the use of complex and computationally expensive Verifiable Computation cryptographic techniques. OP_CAT would remove this requirement on Verifiable Computation, making such protocols far more practical to build in Bitcoin.

Tree signatures provide a multisignature script whose size can be logarithmic in the number of public keys and can encode spend conditions beyond n-of-m. For instance a transaction less than 1KB in size could support tree signatures with up to 4,294,967,296 public keys. This also enables generalized logical spend conditions.

Post-Quantum Lamport signatures in Bitcoin transactions. Lamport signatures merely require the ability to hash and concatenate values on the stack. [4] It has been proposed that if ECDSA is broken or a powerful computer was on the horizon, there might be an effort to protect ownership of bitcoins by allowing people to mark their taproot outputs as "script-path only" and then move their coins into such outputs with a leaf in the script tree requiring a Lamport signature. It is an open question if a tapscript commitment would preserve the quantum resistance of Lamport signatures. Beyond this question, the use of Lamport Signatures in taproot outputs is unlikely to be quantum resistant even if the script spend-path is made quantum resistant. This is because taproot outputs can also be spent with a key. An attacker with a sufficiently powerful quantum computer could bypass the taproot script spend-path by finding the discrete log of the taproot output and thus spending the output using the key spend-path. The use of "Nothing Up My Sleeve" (NUMS) points as described in BIP-341 to disable the key spend-path does not disable the key spend-path against a quantum attacker as NUMS relies on the hardness of finding discrete logs. We are not aware of any mechanism which could disable the key spend-path in a taproot output without a soft-fork change to taproot.

Non-equivocation contracts in tapscript provide a mechanism to punish equivocation/double spending in Bitcoin payment channels. OP_CAT enables this by enforcing rules on the spending transaction's nonce. The capability is a useful building block for payment channels and other Bitcoin protocols.

Vaults [6] which are a specialized covenant that allows a user to block a malicious party who has compromised the user's secret key from stealing the funds in that output. As shown in OP_CAT is sufficient to build vaults in Bitcoin.

Replicating CheckSigFromStack which would allow the creation of simple covenants and other advanced contracts without having to pre-sign spending transactions, possibly reducing complexity and the amount of data that needs to be stored. Originally shown to work with Schnorr signatures, this result has been extended to ECDSA signatures.

OP_CAT was available in early versions of Bitcoin. In 2010, a single commit disabled OP_CAT, along with another 15 opcodes. Folklore states that OP_CAT was removed in this commit because it enabled the construction of a script whose evaluation could have memory usage exponential in the size of the script. For example, a script that pushed a 1-byte value on the stack and then repeated the opcodes OP_DUP, OP_CAT 40 times would result in a stack element whose size was greater than 1 terabyte assuming no maximum stack element size. As Bitcoin at that time had a maximum stack element size of 5000 bytes, the effect of this expansion was limited to 5000 bytes. This is no longer an issue because tapscript enforces a maximum stack element size of 520 bytes.”

The last update of the BIP was done on Sep. 8 2024 by Ethan Heilman

Controversy

The controversy revolves around two main camps:

1. Those who want to preserve Bitcoin’s network for monetary transactions only, arguing that adding smart contract capabilities could introduce risks and complexity.
2. Others who advocate for expanding Bitcoin’s capabilities to support a wider range of applications, seeing OP_CAT as a step towards enhancing the network’s utility.

Final Thoughts

Bitcoin have done what no other asset have done in history, neither gold, its success is clear, and now, that BlackRock is involved, “miraculously”, corporations and governments are getting on board and Bitcoin is not anymore only for criminals or “rat poison” or “is going to zero”.

But as all tech, improvements are important, if those improvements are done to secure more the network and to make it more robust, there will be little to none controversy, however, when those changes are aiming at adding new shinning features that would change Bitcoin into a network with similar features as Ethereum in terms of contracts that requires attention and debate, few questions come to mind:

1. How will that change affect the security of the network?
2. How that change will affect the blockchain usage?
3. What is the projected impact over the fees per transaction if this change is approved?
4. Will the impact create pressure for the block size increase discussion to come back to the table and with it a second war?

Looking into Ethan Heilman work and contribution to the Bitcoin ecosystem, I am inclined to believe that he has considered most of those questions.

Looking forward to observe the evolution of this proposal.

You liked the article? Make my day brighter!

Like and share!

Last but not least, the following link is an unstoppable domain, it will open a page in which you can perform an anonymous contribution to support my work:

https://rodswallet.unstoppable/

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To open the link you need to use a best in class browser that supports web3, two are recommended: Brave Browser and Opera Browser

A Step Towards Enhanced Transaction Privacy in Bitcoin.

Bitcoin Silent Payments, also known as BIP352[^1], is a proposed improvement to Bitcoin’s payment system that has been gaining traction for its potential to bolster transaction privacy in Layer 1.

In simple terms, Silent Payments enables users to:

• Generate a single, reusable static address for receiving payments, as a business this is a game changer since it make it possible to proceed with the proper financial operational security (OpSec).

• Send and receive bitcoins without disclosing transaction details to third parties, such as the person or business you pay to, cybercriminals and chain analysis companies that sell that data to anyone willing to pay for it, that will include cybercriminals or simply; if you are a business; your competitors… When you use Silent Payments, only the sender and the receiver can connect it checking the on chain activity.

• Without Silent Payments, if you are a non profit organization, public fund raiser, independent journalist, or business you needed support to setup a proper infrastructure to handle the donations or payments in a private manner. With Silent Payments, you post in your web site a single address in text format or as a QR code to receive donations or payments for goods, that simple.

Can I Use Silent Payments Already?

Yes, but it is currently only available through select wallets that have implemented the feature. Users must have compatible wallets and ensure that both parties involved in the transaction have Silent Payments enabled. Currently, leading wallets like Blue Wallet, and others like Cake Wallet and BitBox has adopted the feature. It's essential to verify compatibility before making transactions.

Current wallets known to support it as of writing this article:

• BlueWallet -- Only for sending
• Cake Wallet -- Send, receive, Privacy Preserving Scanning
• Silentium -- Proof of concept, good for testing
• BitBox -- Only for sending

Summarizing:

PROS:

• Enhanced Privacy
• Increased Security
• Improved User Experience
• Cheap and seamless implementation for non profit organization, fund raisers and businesses alike.

CONS:

• None

Final Thoughts

As Bitcoin continues to evolve, Silent Payments will play a significant role in enhancing transaction privacy and security. The potential benefits are undeniable and substantial.

In the near future, we can expect wider adoption and implementation of Silent Payments as more wallets and exchanges embrace this groundbreaking feature. Looking forward to see Phoenix, Sparrow, Ashigaru[^2] and Electrum adoption.

I will suggest all of us start contacting in all social networks the wallets we us and encourage them to implement Silent Payments

Here the contact info for some of them:

• Phoenix: https://twitter.com/PhoenixWallet
• Ashigaru: contact@ashigaru.rs (if you want a response, send your email signed with PGP)
• Sparrow Wallet: https://twitter.com/SparrowWallet, https://t.me/SparrowWallet
• Electrum: https://twitter.com/ElectrumWallet

[^1]: Here the link to the BIP352: https://bips.dev/352/
[^2]: Ashigaru is a fork of Samurai Wallet performed by anonymous developers (IMO, all Bitcoin related development should be anonymous, to protect the project from nefarious players, unfortunately, most developers in the arena choose to be “public” figures, hence, becoming a target of current and potential Bitcoin enemies and a weak link for the ecosystem)
Ashigaru in Japanese means “light feet” (translated as foot soldiers or peasants)

Nowadays, businesses and individuals are adopting Bitcoin as a method of payment. It's no surprise, given the security, speed, and cost-efficiency associated with it, specially using the LN. However, despite the numerous advantages, Bitcoin still faces challenges in terms of privacy, fees, and scalability.

What is ARK?

A Layer 2 protocol for Bitcoin designed to solve some of the Bitcoin Network challenges, to improve its efficiency, security and scalability. The protocol aims to enhance the functionality of Bitcoin by addressing its current limitations by using a shared UTXO model that enables anonymous, off-chain payments through an untrusted intermediary called the Ark Service Provider (ASP). ASPs are always-on servers that provide liquidity to the network, similar to how Lightning service providers work but without the time consuming opening and close and balancing of channels.

Interoperability with the Lighting Network?

Ark will function as a liquidity network that operates like Lightning, but without introducing liquidity constraints or a direct link between the sender and receiver. It uses virtual UTXOs, to enable anonymous, scalable, off-chain payments. ASPs provide liquidity to the network and charge fees for their services.

ARK will address key issues with deploying capital into the Lightning Network providing a layer that settles transactions without the requirement for a specific infrastructure to remain online, as is the case with Lightning, while still providing assurances of the private custody of funds. How:

• Ark can interoperate with Lightning by attaching HTLCs (Hashed Timelock Contracts) and PTLCs (Point Time Locked Contracts) to a pool transaction. Attached HTLCs live under another shared UTXO called the HTLCs outputs, which expires after four-weeks.
• Ark service providers forward HTLCs to the broader Lightning Network the moment after HTLCs are attached to a pool transaction. This requires Ark service providers to run routing nodes on the Lightning Network with well-established outgoing channels. Ark users can also get paid from Lightning using HTLC-nested vTXOs.

Last but not least, the Ark Service Provider will serve not only as a liquidity provider but as a Coin-Join coordinator and a Lightning service provider.

How does ARK compares with the Lighting Network?

Conclusion

The ARK protocol is an exciting development, addressing many of the challenges faced by Bitcoin Network today. ARK promises to enhance, above all, privacy and scalability, making it a valuable addition to the rapidly growing Bitcoin ecosystem.

_

Sources and recommended watching and reading:

• Ark Whiteboard Masterclass with Burak & Robin - MUST WATCH
• ArkPillMe
• GitHub
• Community Telegram Channel
• ARK video from Bitcoin Miami 2023
• ARK presentation from Bitcoin Miami 2023

"Files" by Google added a "feature"... "Smart Search", you can toggle it to OFF and it is highly recommended to do so.

Toggle the Smart Search to OFF, otherwise, google will search and index every picture, video and document in your device, no exceptions, anything you have ever photographed and you forgot, any document you have downloaded or article, etc...

How this could affect you?

Google is actively combating child abuse and therefore it has built in its "AI" a very aggressive algorithm searching of material that "IT THINKS" is related, therefore the following content could be flagged:

• Pictures of you and your children in the beach
• Pictures or videos which are innocent in nature but the "AI" "thinks" are not
• Articles you may have save for research to write your next essay that have links to flagged information or sites

The results:

• Your google account will be canceled
• You will be flagged as a criminal across the digital world

You think this is non sense? Think again:
https://www.nytimes.com/2022/08/21/technology/google-surveillance-toddler-photo.html

How to switch it off:

1. Open files by Google
2. Tap on Menu -> Settings
3. Turn OFF Smart Search

But you can do more for your privacy and the security of your family

1. Stop using google apps, if possible get rid off of Google OS and use Graphene OS
2. Go to Settings -> Apps
3. Search for Files by Google
4. Unistall the app, if you can't disable it
5. Keep doing that with most Google apps that are not a must if you have not switched already to GrapheneOS

Remember, Google keeps advocating for privacy, but as many others have pointed out repeatedly, they are the first ones lobbying for the removal of your privacy by regulation and draconian laws, their hypocrisy knows no limits

Recommendation:

I would assume you have installed F-Droid in your android, or Obtainium if you are more advanced, if so, consider "Simple File Manager Pro" by Tibor Kaputa, this dev has a suite of apps that are basic needs and the best feature in my opinion is that not one of his apps connect to the internet, contacts, gallery, files, phone, etc.

Note
As most people, we all love the convenience of technology, it makes our lives easier, however, our safety and our family safety should go first, between technology being miss-used and abused by corporations and cyber-criminals data mining and checking for easy targets to attack for profit, we need to keep our guard up. Learning is key, resist the use of new tech if you do not understand the privacy trade offs, no matter how appealing and convenient it looks like. .

Please leave your comments with your favorite FOSS Files app!