From mboxrd@z Thu Jan 1 00:00:00 1970 Delivery-date: Wed, 19 Mar 2025 17:08:10 -0700 Received: from mail-ot1-f56.google.com ([209.85.210.56]) by mail.fairlystable.org with esmtps (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256 (Exim 4.94.2) (envelope-from ) id 1tv3SD-0003LK-6t for bitcoindev@gnusha.org; Wed, 19 Mar 2025 17:08:10 -0700 Received: by mail-ot1-f56.google.com with SMTP id 46e09a7af769-72a0de193b2sf283167a34.3 for ; Wed, 19 Mar 2025 17:08:09 -0700 (PDT) ARC-Seal: i=2; a=rsa-sha256; t=1742429283; cv=pass; d=google.com; s=arc-20240605; b=dWsaBrZcg3CziCq5UxCqdbG4O0rPFuCBcmhoK2Vf9TPPROGD6gV8HU9xstayXmXvqJ EBFXQ6yYVN0D3Gi1cDsF7OhMPF5bfCmjgjmQ2hJNFa+DNLOAQLADMXu5KTRKaFuXLjWd gv9dKdp3OpCxffHJecPLu84+wba+nScRuxcz3idLxWACAh9S6Mhne1/jUwNOVDnERnDz lrCP94N+LxKWrIWIikGLCvLfiv8LSqCk8XZ+3o7uqbaWwen8Ag6hauIRuosfnJN+EOOZ 0RGt6lRRLnKmkSaZ3fLgqR7pbR9Wykc7KY9lWubFlU8GWsB17z27ttR4TyLeXk4D6+O9 V6Yg== ARC-Message-Signature: i=2; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20240605; h=list-unsubscribe:list-subscribe:list-archive:list-help:list-post :list-id:mailing-list:precedence:cc:to:subject:message-id:date:from :in-reply-to:references:mime-version:sender:dkim-signature :dkim-signature; bh=+EGwtQfYmYk9Ivo0pcBJCrNIxvPcRdYyBnT42FEZZ8k=; fh=+sSBCxvAA9RP7CYGlR9LttFOtWWUbU/0faTWb9FNYjo=; b=VKligD4GCa3UM3J+0DV7BolzIA1uZVWhnsrVwE07zz7l1RIvS9aRlv/sE4KpZrQHIH 73hbDk5l78t0zEHQQqbtLdskl/2ZLhcv4lk5PGdawAokj1+dxsZixQhX7BMDplAyxxMy a1gH0JCbv2VVMZMA9O/yspx1ck9BHBvjD863XRG1sXmlAi40/87Q+lY16c6JxVCw5G00 Mq4da/qwisaHl2vxh5P1AmassJVFhiRj6eIuHEFdQe+5KdqZjWK3pJVrPNKsuCc4OwFm Ifa/L5GFIicuEHYujB3Pj4lwrPlNLdHLFUj+/gbdDpbmxKFpY+vja7oj6PNAS/KwqD2I m54Q==; darn=gnusha.org ARC-Authentication-Results: i=2; gmr-mx.google.com; dkim=pass header.i=@gmail.com header.s=20230601 header.b=b1PO58da; spf=pass (google.com: domain of melvincarvalho@gmail.com designates 2607:f8b0:4864:20::102a as permitted sender) smtp.mailfrom=melvincarvalho@gmail.com; dmarc=pass (p=NONE sp=QUARANTINE dis=NONE) header.from=gmail.com; dara=pass header.i=@googlegroups.com DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=googlegroups.com; s=20230601; t=1742429283; x=1743034083; darn=gnusha.org; h=list-unsubscribe:list-subscribe:list-archive:list-help:list-post :list-id:mailing-list:precedence:x-original-authentication-results :x-original-sender:cc:to:subject:message-id:date:from:in-reply-to :references:mime-version:sender:from:to:cc:subject:date:message-id :reply-to; bh=+EGwtQfYmYk9Ivo0pcBJCrNIxvPcRdYyBnT42FEZZ8k=; b=m1GgjkPmgjRmCgIqOqoZfrR6lBKmxTNrvdyohmiAK+pzFBL5E8WmTzv+fMg9XHXJ1e ED7rbP4sF/LB9RJowPUzyUMeoVOxIwvRTH/Lvvs25Kg5i69rfulR8IIKkUG9yOaokl/X Bf+ahTd4x/nGNeLFp7DQCVQx2NJnam9h1sztHoGXNyMNdeAaobiwK/MfCKfuEfI7hz8z 1/Jn8tRMLAdFZbW4dRMcRyBd1lQoraCjrT8Ufbce3slgTCRV/MBfNABFokTamWDZEoHL D6g/Rl/g51wAeVnAh72qi7CY125EdRKK2S3Hvvmt3g5i+xB1H8P7t4xqw6WRwFC9sr9e qTLA== DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1742429283; x=1743034083; darn=gnusha.org; h=list-unsubscribe:list-subscribe:list-archive:list-help:list-post :list-id:mailing-list:precedence:x-original-authentication-results :x-original-sender:cc:to:subject:message-id:date:from:in-reply-to :references:mime-version:from:to:cc:subject:date:message-id:reply-to; bh=+EGwtQfYmYk9Ivo0pcBJCrNIxvPcRdYyBnT42FEZZ8k=; b=WIJ6RSp75FPi8bEo2el5rIXpjL5Rc2MQIfnkfG1AsffxYqZnnyEyVvCgvHP8hkj7l7 28tIPOH+V7Y5kwWjvvXZBZi0EghZr1RKsya/G6Ki3uf/K3Aaas8SJ3kp8OOy2V1oX73a geltHXoH1m0uIEwTwfbTJHo5QW5Ts9Bk3DayZ8PPd6tNJLigWB2TvlXKnc31VDV42ay5 7N0T8VypqEFl1llUYjlDI/cnfDI2IoUXRT6KdE0cRJkV92rsBnLrwuvGGmABjYeQXSs7 HeYlTOxEMbQi1ppop6mdEW79LqCNsgxQGO2pEXWPFTkz1UOFCpci38LnvE5USRj8ENrL ygOA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1742429283; x=1743034083; h=list-unsubscribe:list-subscribe:list-archive:list-help:list-post :list-id:mailing-list:precedence:x-original-authentication-results :x-original-sender:cc:to:subject:message-id:date:from:in-reply-to :references:mime-version:x-beenthere:x-gm-message-state:sender:from :to:cc:subject:date:message-id:reply-to; bh=+EGwtQfYmYk9Ivo0pcBJCrNIxvPcRdYyBnT42FEZZ8k=; b=DvT+M0MDWoZX0fIoI56YFNh/4nX+KnZlL+80G9pS2YgkLwdGb/FLKfwDuHkq7jUcYe 2vU5hUgPwI5zfqPMHI+BtpeuOFuBcDEpphPXUffGheyP8P9wlC3uMpTxh7EV+2Pu1K9C GYEqeF1aKhYxuQHBmHE6g5Y8buVHICrLMxN30YXCAN2vW9sKMOcEh6lgutYJWh1ybOID cQpJwxqJjGzo6khQegzPCHplIMV1k7gLUUBhPO/4lCmzQVWMkQddnCjwlGwj+87XZ0W5 KhCjmQ+2GmuFgqp6vTPbtq4wyrJgMhQS9PWbJORzB+9JexQIuzc64V9l7H55Iox4G7qg VVLw== Sender: bitcoindev@googlegroups.com X-Forwarded-Encrypted: i=2; AJvYcCWDAUTnCW07fe/cco6+O0XeVmWbOlmuOneg/2GN1zBLjb76f9yLdJKkZ+dg7++pQq+8n2T36jXi3cqO@gnusha.org X-Gm-Message-State: AOJu0Yz5d8A6EkUDt7Y3x5b+erA4TqSiqIEX4UcuZ22bWpQ5sj85i3rM K83n8pZu5T20HqKAZ4g1Nr1ZuHECLTayFfvYAxHb4D3P2+6btlKx X-Google-Smtp-Source: AGHT+IFOgzGRyEoedHWHPn4kMUT4W6dfAref9jPxiH1Bs8sLHP8X7JCtHCyYtP+3D9hp6otkx7z8kQ== X-Received: by 2002:a05:6830:349e:b0:72b:8974:e3db with SMTP id 46e09a7af769-72c02e77dacmr1176899a34.25.1742429283448; Wed, 19 Mar 2025 17:08:03 -0700 (PDT) X-BeenThere: bitcoindev@googlegroups.com; h=ARLLPAJ0THRo6mRgP/TRvK7rwszAseKIno5VEgGI3P3Z8iIFDA== Received: by 2002:a4a:b283:0:b0:601:a5e9:6391 with SMTP id 006d021491bc7-60228d8901als133368eaf.0.-pod-prod-09-us; Wed, 19 Mar 2025 17:08:00 -0700 (PDT) X-Received: by 2002:a05:6808:1527:b0:3f9:641b:63ef with SMTP id 5614622812f47-3feb4b808a0mr994948b6e.28.1742429280584; Wed, 19 Mar 2025 17:08:00 -0700 (PDT) Received: by 2002:a05:6808:394a:b0:3fa:da36:efcd with SMTP id 5614622812f47-3feac90f881msb6e; Wed, 19 Mar 2025 02:11:42 -0700 (PDT) X-Received: by 2002:a05:6e02:1fe9:b0:3d4:2306:6d0 with SMTP id e9e14a558f8ab-3d586b9ed15mr17251035ab.14.1742375501526; Wed, 19 Mar 2025 02:11:41 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1742375501; cv=none; d=google.com; s=arc-20240605; b=EVddn3RmBaB8olfkDg+d5OSC2SMWD7axJ5dQlMTWx9/y9l5lgpW/bt1Wx++E/eYc2V 8p8MlEGOTkVc/fUpsPDeUbY3WrE/aTtLRjm7WLNNLTJ0NrzQZdL68KTzUy+Wib0i0h4C lO7EkVu3CYFvUm6+mw1sCTGDKSnSLAOn/+NB8cWZM6YYle2AIrxRK3PgHw0WEeXalRsZ AjlbyXdyY0/LNEqvrGljM0X627LbUoyPw0YbuyWAxMjmaa6f+QFNkQSigZYmxLZrgBnL QeakKngELC3H39jc/4Y+YbwcGdvUHb44B1ht5ne7B89JnPEUE3nInbKbofrelLxdOUHI Jgwg== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20240605; h=cc:to:subject:message-id:date:from:in-reply-to:references :mime-version:dkim-signature; bh=A1bU9ApHokleQLa/3dxOSn0om1D+CoYs79efoz57mHE=; fh=Kq6uqhrB3Y2LVd2m1sYXSJq9UR3UoZYIYVPgbiDxK0k=; b=aO3UDWXHqubUHoQdIw8uEmgLOjP6rIQnsUjTfECGBSWFWO31SoYwQlPUWA4+ngEVCH ruh7UQ7Xqe1GDlS/aaqhjEh0yh54ufGHDoz4hXkcELBg/0BVzVTGHHpqXNH/doBfIncn 2teMdysatvmp05Yj4jezOD9s7qTXBz2zxPATns8kYKopzCCiCERPHBefa9frrLWgJbsg PTElhsGT+Qx8KqbFERuI/8eEEh/sgNjTxoNO/cVGUR38QAfj3yRtsNN1mPs/Qo/yYHod TanrnzQx0tLa1RCkU+RXk6FJ0uAf8TOY5YdE3/ymGrDKp8U++Rpt2lnaU1n8B1I7Cfgh F7ew==; dara=google.com ARC-Authentication-Results: i=1; gmr-mx.google.com; dkim=pass header.i=@gmail.com header.s=20230601 header.b=b1PO58da; spf=pass (google.com: domain of melvincarvalho@gmail.com designates 2607:f8b0:4864:20::102a as permitted sender) smtp.mailfrom=melvincarvalho@gmail.com; dmarc=pass (p=NONE sp=QUARANTINE dis=NONE) header.from=gmail.com; dara=pass header.i=@googlegroups.com Received: from mail-pj1-x102a.google.com (mail-pj1-x102a.google.com. [2607:f8b0:4864:20::102a]) by gmr-mx.google.com with ESMTPS id e9e14a558f8ab-3d47a4491efsi5353655ab.0.2025.03.19.02.11.41 for (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Wed, 19 Mar 2025 02:11:41 -0700 (PDT) Received-SPF: pass (google.com: domain of melvincarvalho@gmail.com designates 2607:f8b0:4864:20::102a as permitted sender) client-ip=2607:f8b0:4864:20::102a; Received: by mail-pj1-x102a.google.com with SMTP id 98e67ed59e1d1-2ff65d88103so8594246a91.2 for ; Wed, 19 Mar 2025 02:11:41 -0700 (PDT) X-Gm-Gg: ASbGncu5nWPeodqB4gXKusKJ6B47Rwf/DpOmUJkym/YRoZAdy/uTw3JVFDYIqcYSudV omXt+Z4ibENWJ65wQFw9PKveMlSYsRVOI3GBroN0HfPONl4wPRwathfGLGp8Hw1XmoQHfw4WtQi 3JjN/WUtnVzBJ2vRXaa619Z1vR X-Received: by 2002:a17:90b:1c88:b0:2fe:80cb:ac05 with SMTP id 98e67ed59e1d1-301bde763f0mr3371884a91.9.1742375500682; Wed, 19 Mar 2025 02:11:40 -0700 (PDT) MIME-Version: 1.0 References: <2064B7F4-B23A-44B0-A361-0EC4187D8E71@sprovoost.nl> In-Reply-To: <2064B7F4-B23A-44B0-A361-0EC4187D8E71@sprovoost.nl> From: Melvin Carvalho Date: Wed, 19 Mar 2025 10:11:28 +0100 X-Gm-Features: AQ5f1JqZ0Mq0PrCpEn_yN8dSwaW-Al2T_C6uWsqT8II-Er7ZidZJEzUld_mAIuY Message-ID: Subject: Re: [bitcoindev] Unbreaking testnet4 To: Sjors Provoost Cc: "'Antoine Poinsot' via Bitcoin Development Mailing List" , Antoine Poinsot Content-Type: multipart/alternative; boundary="000000000000c89c7c0630ae68f9" X-Original-Sender: melvincarvalho@gmail.com X-Original-Authentication-Results: gmr-mx.google.com; dkim=pass header.i=@gmail.com header.s=20230601 header.b=b1PO58da; spf=pass (google.com: domain of melvincarvalho@gmail.com designates 2607:f8b0:4864:20::102a as permitted sender) smtp.mailfrom=melvincarvalho@gmail.com; dmarc=pass (p=NONE sp=QUARANTINE dis=NONE) header.from=gmail.com; dara=pass header.i=@googlegroups.com Precedence: list Mailing-list: list bitcoindev@googlegroups.com; contact bitcoindev+owners@googlegroups.com List-ID: X-Google-Group-Id: 786775582512 List-Post: , List-Help: , List-Archive: , List-Unsubscribe: , X-Spam-Score: -0.5 (/) --000000000000c89c7c0630ae68f9 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable st 19. 3. 2025 v 10:04 odes=C3=ADlatel Sjors Provoost napsal: > Antoine Poinsot wrote: > > The given rationale for a difficulty reset was to let developers > occasionally mine blocks on their laptop. But you cannot have your cake a= nd > eat it too: either the network is permissionless (PoW) or you assign > identities and privileges to some (Signet). By trying to do both at the > same time testnet4 created a loophole for abuse. As a result it failed on > both count: it neither mimics mainnet nor allows developers to mine activ= e > blocks on their laptop. > > > Let me clarify why developers can't mine on their own laptop with testnet= 4. > > The way you would do that is to move your computer clock forward by 20 > minutes (or use faketime), at which point the difficulty drops to 1. You > would then mine your (presumably non-standard transaction) and broadcast = it > to the network. > > This is also the strategy used to acquire more testnet coins if you don't > have an ASIC and don't want to use a faucet. > > On testnet3 the latter wasn't very productive because at height 4 million > the block subsidy is under 10k sats. > > But on testnet4 every block yields 50 tBTC. So several people try to mine > such a block, leading to the many parallel forks. > > If you're a developer trying to mine a non-standard transaction, you have > to be fast, well connected and lucky to be the first block picked up by t= he > rest of the network. > > But why mine just one if you can mine many? > > Some CPU miners are now mining as many testnet4 blocks as they can by > bumping their clock 20 minutes not just once, but several times in a row. > Until they run against the limit other nodes put on how far a block can b= e > in the future, namely two hours. So when a real difficulty block appears, > you may see 5 blocks on top of it instantly. > > This behavior is even worse from the point of view of a developer trying > to mine a non-standard transaction. Because the tip of your node is alway= s > going to be about two hours in the future, when you mine on top of that b= y > moving your clock even further, it will be rejected by your peers. > > So this use case of CPU mining non-standard transactions is simply dead a= s > long as this behaviour exists. We might as well reduce code complexity. > > That said, testnet will never mimic mainnet. It has no value, or worse, > very little value. So the incentives are different, which leads to > different behavior. That's a whack-a-mole game, which we should probably > not dedicate time to. > The question I=E2=80=99ve had for some time is why spoofed blocks on testne= t4 come in batches of: - 6 blocks -20-minute intervals - A maximum lead time of 2 hours If these values were set for early Bitcoin network reasons, would it make sense to tweak them for testnet4 to improve functionality? Reducing the maximum lead from 2 hours to 1 hour and limiting batches to 3 blocks instead of 6 seems like it could mitigate some of the observed issues while maintaining testnet=E2=80=99s purpose. Would this be feasible? > > - Sjors > > > > -- > You received this message because you are subscribed to the Google Groups > "Bitcoin Development Mailing List" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to bitcoindev+unsubscribe@googlegroups.com. > To view this discussion visit > https://groups.google.com/d/msgid/bitcoindev/2064B7F4-B23A-44B0-A361-0EC4= 187D8E71%40sprovoost.nl > > . > --=20 You received this message because you are subscribed to the Google Groups "= Bitcoin Development Mailing List" group. To unsubscribe from this group and stop receiving emails from it, send an e= mail to bitcoindev+unsubscribe@googlegroups.com. To view this discussion visit https://groups.google.com/d/msgid/bitcoindev/= CAKaEYhLNTbA%3DqMuQ5W63jxwUoa2%2Bmpn020NC31JqGzbk0wPF-A%40mail.gmail.com. --000000000000c89c7c0630ae68f9 Content-Type: text/html; charset="UTF-8" Content-Transfer-Encoding: quoted-printable


st 19. 3. 2025 = v=C2=A010:04 odes=C3=ADlatel Sjors Provoost <sjors@sprovoost.nl> napsal:
Antoine Poinsot wrote:

= The given rationale for a difficulty reset was to let developers=20 occasionally mine blocks on their laptop. But you cannot have your cake=20 and eat it too: either the network is permissionless (PoW) or you assign identities and privileges to some (Signet). By trying to do both at the same time testnet4 created a loophole for abuse. As a result it failed=20 on both count: it neither mimics mainnet nor allows developers to mine=20 active blocks on their laptop.

=
Let me clarify why developers can't mine on their own laptop= with testnet4.

The way you would do that is to mo= ve your computer clock forward by 20 minutes (or use faketime), at which po= int the difficulty drops to 1. You would then mine your (presumably non-sta= ndard transaction) and broadcast it to the network.

This is also the strategy used to acquire more testnet coins if you don&#= 39;t have an ASIC and don't want to use a faucet.

<= /div>
On testnet3 the latter wasn't very productive because at heig= ht 4 million the block subsidy is under 10k sats.

= But on testnet4 every block yields 50 tBTC. So several people try to mine s= uch a block, leading to the many parallel forks.=C2=A0

=
If you're a developer trying to mine a non-standard transaction, y= ou have to be fast, well connected and lucky to be the first block picked u= p by the rest of the network.

But why mine just on= e if you can mine many?

Some CPU miners are now mi= ning as many testnet4 blocks as they can by bumping their clock 20 minutes = not just once, but several times in a row. Until they run against the limit= other nodes put on how far a block can be in the future, namely two hours.= So when a real difficulty block appears, you may see 5 blocks on top of it= instantly.

This behavior is even worse from the p= oint of view of a developer trying to mine a non-standard transaction. Beca= use the tip of your node is always going to be about two hours in the futur= e, when you mine on top of that by moving your clock even further, it will = be rejected by your peers.

So this use case of CPU= mining non-standard transactions is simply dead as long as this behaviour = exists. We might as well reduce code complexity.

T= hat said, testnet will never mimic mainnet. It has no value, or worse, very= little value. So the incentives are different, which leads to different be= havior. That's a whack-a-mole game, which we should probably not dedica= te time to.

The question I=E2=80=99v= e had for some time is why spoofed blocks on testnet4 come in batches of:
- 6 blocks
-20-= minute intervals
- A maximum lead time of 2 hours

If these values= were set for early Bitcoin network reasons, would it make sense to tweak t= hem for testnet4 to improve functionality? Reducing the maximum lead from 2= hours to 1 hour and limiting batches to 3 blocks instead of 6 seems like i= t could mitigate some of the observed issues while maintaining testnet=E2= =80=99s purpose.

Would this be feasible?
=C2=A0

- Sjor= s


=C2=A0
--
You received this message because you are subscribed to the Google Groups &= quot;Bitcoin Development Mailing List" group.
To unsubscribe from this group and stop receiving emails from it, send an e= mail to bitcoindev+unsubscribe@googlegroups.com.
To view this discussion visit https://groups.google.c= om/d/msgid/bitcoindev/2064B7F4-B23A-44B0-A361-0EC4187D8E71%40sprovoost.nl.

--
You received this message because you are subscribed to the Google Groups &= quot;Bitcoin Development Mailing List" group.
To unsubscribe from this group and stop receiving emails from it, send an e= mail to bitcoind= ev+unsubscribe@googlegroups.com.
To view this discussion visit https://groups.google.com/= d/msgid/bitcoindev/CAKaEYhLNTbA%3DqMuQ5W63jxwUoa2%2Bmpn020NC31JqGzbk0wPF-A%= 40mail.gmail.com.
--000000000000c89c7c0630ae68f9--