OSK Prezzo

[CHIP] Unforgeable Groups V6.0 Decentralized Applications on Bitcoin Cash

<!-- SC_OFF --><div class="md"><p>About a week ago Jason had pinged me and gave me a heads up that he's working on something, and today he has <a href="https://old.reddit.com/r/btc/comments/sz0q1g/chip_cashtokens_v2_token_primitives_for_bitcoin/">announced that something</a>, and it resembles Group Tokens quite a bit, which is great! Great because he built it from scratch and independently arrived to something very similar, and to me it's a validation of the Group approach :)</p> <p>I am also thankful to him, because his ping prompted me to revisit <a href="https://gitlab.com/0353F40E/group-tokenization/-/issues/19">Thomas Zander's idea</a> of using the TXID as the groupID (or categoryID), and looking at that part of "idea space" again, I discovered something better than I could have imagined, a facility that could seamlessly let us transition from contract to contract from commitment to commitment from token to token.</p> <p>I held off broadly announcing V6.0 because I was waiting to see what Jason's been working on, and I find it cool that it's so similar, because its an independent validation of the Group approach :)</p> <p>I've been bouncing Group for months now, and we really worked hard to making the consensus layer as simple as possible, and I think that with V6.0 we can implement everything CT2.0 promises while keeping consensus layer simple and using Script for the flexibility it provides.</p> <p>Without furder ado, copying the <a href="https://bitcoincashresearch.org/t/chip-2021-02-group-tokenization-for-bitcoin-cash/311/53">announcement</a> from research forum.</p> <p><a href="https://gitlab.com/0353F40E/group-tokenization/-/merge_requests/18">MAJOR UPDATE - 6.0</a></p> <p>This was prompted by exchanging notes with @bitjson and revisiting @tom 's idea of <a href="https://gitlab.com/0353F40E/group-tokenization/-/issues/19">declaring the genesis</a>, and it enables group tokens to interact so much better with Script!</p> <p>Changes:</p> <ul> <li>Whole new approach to group genesis: instead of inferring it from the TX, it will be explicitly declared as an input prefix that can use the same byte because it will be exclusive to input context.</li> <li>One more introspection opcode to access the genesis input's generated <code>groupID</code> preimage.</li> <li>Change group amount format from VarInt to fixed width uint.</li> </ul> <p>Instead of inferring genesis from orphan outputs and allowing orphans only if the groupID matches the hash, we require the genesis to be declared on the inputs, conceptually similar to a coinbase input. A new introspection opcode is added to access the input's genesis preimage. Advantages:</p> <ul> <li>enables flexibility in deciding which input will be a genesis input</li> <li>enables flexibility in deciding which input's prevout will be committed to for later use in smart contracts</li> <li>enables better interaction with contracts requiring or verifying the genesis operation</li> <li>removes malleability from group genesis (outputs are signed, and orphans disallowed)</li> <li>more consistent with Bitcoin design (coinbase input)</li> <li>enables versioning the genesis preimage construction without having to spend scarce group type bits which will be reserved for potential "super-contract" optimizations in the future</li> <li>opens the path to a future upgrade where user-defined parts of the genesis TX could be appended to the preimage</li> <li>enables a dedicated genesis nonce field which simplifies grinding the group type, making the group type encoding time-space trade-off more convenient</li> <li>opens the path to synergies with detached proofs and signatures, where hash of the real unlocking script could be appended to the groupID preimage</li> </ul> <p>Example - "Jason's Challenge" Contract - <a href="https://ide.bitauth.com/import-template/eJzVWgtv2zgS_iuE94BrgTQl9aCkogig2HKTazb22U6vxe3BoCQq1sWWfJKcBxb7329ISrIedpruXW976cMyORzODGeG34zy6-BPebDiGzZ4N1gVxTZ_9_atHxdsV6xOg3TzVk3mb8UAT4o4YEWcJm8KvtmuWcHf3ONTRXL6zzxNBieDkOdBFm8FFbBcrDja5TxDW_aUI4JPMMYoZ0War-IcFSm65QVi8HDHk1ME1E8oYAkqMpbkESwrVqxQs4IYOCHtTRq90U-QEAf5LLgTE3mc3K45fNyWEyHfpnlciC_lcpaEcjO1ZMXjrCdOlKUbuWLLMtAVBek9T1hSnIJaCdtw0OcvDLT8c46GK7Ze8-SWw5QwSxHzfPDu199OBkp78WVQCpFmT8sgzbZpxpRVfq24jbzpZH65mMy-oOFkNp3M3MXl5HpQMQGKt2_RT-gmWafBHaiI5nL8lwSGF1Irf5clKN0V212B4iTkj78k7_EjJmeSZsqyAumnKI3QbZbutpcjtM14vGG3HL265QnPQes4EYtBZZCp4Fn-WrGofgjGdkiI-Gz-NDYgRzZYsXwlZ5obge2A4h5ERhmPTtVmnDq-jUPTCCxs-Bo2iKFj2wkMjjHnNo2YyYzIdizbsiNOAo45pZREPlBYmFpKmA9H9kkfEvCkV9OPF6Vqmq77gWPRkDnM4TqOImL7ukkckzq67-g2x5Sz6Hmupdcgtkl3SSEZM2zTpp0UgxkPOd-UR4dm7KE8ImJZHtZchxjwqVtUPp2LZ9t2Ry48GYFJ1bgQ-XwIIo9cx3U8HY_HxD6vRD4HkT1MPXesVg7xSLMonJvlEAqLMDEMa2wSa2yZJrFtywSurkXpOUgxtsbwvxwFOhu-2d2zFnNDPPTkEx0OsU2wZrUphiOhD1DB_7r4DsK5GtUxBnKLGhhkEnQU_sCcJuZMouZM0prT5ZxWzmmdOdAINPFcByxFbNgNNPGsofwcgnQjTKgr5ByRQ5qMDso2tITkyl6HJTxA0ZHzIIWUFvxAesJP6KoTx5Pp8sKdXxCKpVOEWmBjLcShzrQAY_DwiBAW-WGIGbWYGVqaHVKbncmV3l9v3Kua9Tze7ERG7vib98iDnUg7csknb3Y5_lKvaZGqMTEYpEleZLugkOmFhyqDgu_3Ytx_QlG8XguVYsVUpE_-uOVBwcM68lU6Q9WlcSopK1uUkyKbFitpBmIpBYfuQmUZbX6BVpyFPIP5vc0QkBoNUgQ_jYhVaRHEluuzvVrSGoJY8BrdTFGfZclqHGd5mUAEn48XaLODAR-uiCy9j0PQUZhgV-wyuH22HDJwlqvVwHM2WaCmbO-rQ1PHIOcuvOHH-eWHxshk5M29qQt3wWR2ho7ots9GKWTYRpLdyoxc7ocf_6hUcFYboSn9ZQJQoFDnwcIw43kuZC_E5Vtdtoo43S6livJOW2LxfVc8pv5TAccY8mUY_D7LaLVlvneKalkAofpbHe9dB4_StKgcXHrJ_vCBZJhuQC9eavH7btzXdcLRTCq5ulvhs0gApbR0ndOTlm-LeC4duyVyuXKrEMbza-Z_c6etxZUy7WSh1OnJCCnpE8_i6EmBwVgoVOYl1gR4EgqVGKi5qQhwcB-VDWoHSsEmhVghzD3zFjeza2nvRnz2V0sR1YW_JEje4h1U1GPRXhuHyyQqekTKout1-oDSZP2ECNpDR9SAjiVWixOltgDJTKazE8khhdHsIQaQzCpEfD1eAIPdOkQ7CSIhf62LeAszN4vPkxw9rGJ4hvMH15E8GMri25X0B_4IzIU0p1KN4lHuHkjtNfSeSGU_zDx34c0WF-71ZCaVEqOX49rfcS-WK-3Fw_VkUdE26bux_rJ00OSKGrddydm7Hom99k8HlNJephT5RqVIT-K-Wb6bTvrLdNK-USftj9fpypvPOwo1QpeIwBpASQYht5TXwRL-lpHVqMJEjLyaziaTMYK_ZU32-mVV2LARnNUNdqgeq4qBhbjqynQMeQwK1oQJ8NCuuX6AH4McFLiupcpSSjfg1oOyzfdDzfRtKEY0y9CgOrOJ4-CIWiGBwo5gI6LUB1Ab-k4YmjQgjsF0LQjoczXS_1Ptw0DSl8J3qGK_P_h4WcVh6ZgaNDJ5YBHfcGyo9XkQcKpzYgamEzHDh0OM_O9UcVQXvLiM0ET4Vn3pNjD5t9XsB27gYMWDO4i1e4kjRGLoAu29KNMKN5aAUo5fJgKvxjLMZbupDFskOZZNsRMFZKUuVZkgYFCB6rtVgoA2PJMCdpOm_C6JS9oKNoBlpPC95Ix6tv4JuaXIbF2j42GaqDEl0TkPmGiq7QV_gHJO1jcC2ElszlHCH5TkogSs0HQJOhXyANAH0INDkfWvXZzJqi7dcMiIyd5owhpgpzyKeSi7dDWADZgSWThTJugAZAV3su6UuJJXyA89sHzP5LTUtESHlWRwJHnlfcKR3lNbXhbz6dXlooIt6ougmE2mCsl1sVs1W3eBMuHrlcyyVxgnRZbmJX6tLNL1YMCxaD-ymLhXi_nCHX5syq7anE1TI9CEIfCy-L4CuHIcolZvqiDK5edF727R7vuJbRIBE4GxpbUZfw3dtrYZxTmTCPZYu09azOfCOaQmPDzo-gIvVFgZo5arV_7dVIrXrV44jHQ_wHrYeV9gVnFUY_N7tt7xJcF30pyd_P4Mpm_imm5fAr28nVNvcCZ5Qwyx9T5V9YuDzgn2q4FGJVDhfckFjjlH6_iOVyW3KAwg3oKMM-HCokeugjCACo2LCi2FmJYpGzhKHjXK2bKnjUpuZTsdsAEUYcrJaqoHuceKgRf7bM2SQHGJ0qzSRvDfyPcF__s642ie7TvdD1JE9CU-EiQ_SIHw_eT9CvgXwH_F11ueLeX2y2r_W5XK06xRAlx4V1Nv9g59mE0gTX_wrr355Vx-SnTQqwWmKfjvhtU90Toka-bSy-e8qNOfev9Ut6LKly0ncly-sgJ2EPcQElkKV7C8DNIqXEDxeL2_M-E2WjxtIbhZAdAmry7C6m3Mm-deucA1LbmWbbNpOSNaR3VvjAJ2d5yQmtTnhkaZQ4kdWroWhRrhVKOUWjoloUF1nzkB49gKRVM-CohFbdPWznrsy1qo5N9KrXUTr9P3mZadrqPa9DbpvpIpd-u9lkG9levDveiSAbEqQeUaWa6VDGDWwM3ZD9XV1tlBuQlLkrRg-wZ0RTT-vJSu1xoF3p7XNlE5U7fK2tSY23ooChEjckInMMwQMD2cn20EpuVbgUko84kd-YRoIdMDnfiR7dvY4iHRA0c7vpfbsGhjP6Lphkkt24G6a-SNe93qdot_fyDiTdcLCw_b-rqT6D0naUTY4QbxMYesqas4-1ShyYqS9LSsSK9FuJ5U4Qs7qahdxwlHul2WCjxvbGqHR5mJ-N47oNq0ByErv-utdtsRcBDIVc3YHrRtAVnB_hniA2C3hckFlVKlDVvhYTyb_NxUpNd5lchScut1utccrulUAZ-8gGJBZPvO7dRI7-Ieu57eLC6vR95nmGmkc3EXlYs7nar2elEcnX9ZeKJqXI6GHRZVFfFtXYAz1Z463pxuizC5WYAOtRCTqWpbHxBFvUQou9qtLVod7EPsZRpyf57cXC-A4CDrA_7U30N1uo_ucDlaAhg9xj80Q07DQGOWboU208wg8M2IaTo2cGQb3DQjm1CD6I5laoEJBoZ_QYADPWIWg2gp5Wkh6bYsDW_r6akJQUoW3dZBm0v79d2zjDqVxiHLfHKvbjw5ecQuvdKk6fZtkHXA-6XhS2zTCwK1h4iG2ikPguOv8X3mVP_T3_KIGDGJb9kUjj4AMh5ZESYEAku3I2bjKGTAUNO4BXeK6WCIQ5tT4IGBGpBKbbbjv9LSyAR1DdrPA5UHv8CGvTrx2ZD-b-WVcvMWbu547uKzPLvhwUAnhxhozzDQuo5_iIH-DAO9w0A_lJMPHEVtuuNnMfhN_FbWbrtNM6hxB-_-PjgfXiw1rOElNgf_OBmUDaPBO_zbvwFJIRAf">Link to Bitauth IDE Template</a></p> <blockquote> <p>The user pays 10,000 satoshis to get a token. They can transfer that token to use 2-of-3, then back to single sig, then deposit the token and get back their 10,000 satoshis from the parent covenant.</p> </blockquote> <p>There are 2 contracts:</p> <ol> <li><p>NFT, placed on the prevout which will be spent as group genesis input and generate the NFT. The prevout script will require that 10,000 sats are paid into a fixed P2SH address (depository corporation covenant). Only the 1st spend is from a P2SH, the genesis input spend: the NFT can then be moved to an ordinary P2PKH and still be able to reclaim the 10,000 by burning itself in the same TX as <em>any</em> covenant UTXO.</p></li> <li><p>The depository corporation covenant is an anyone-can-spend kind of thing, but it requires <em>any</em> NFT that can satisfy the proof of payment at genesis to be burned to an OP_RETURN. The NFT's genesis script is verified to match the template hardcoded in the P2SH covenant.</p></li> </ol> <p>Not only does this create a BCH-backed NFT, it also lets NFT holders reclaim the BCH from <em>any</em> covenant UTXO :) I suspect there's a way to make some kind of BCH mixer based on this.</p> <p>PS, for comparing the 2 proposals, consider how CT2.0 and Group map to each other:</p> <p><code><category_id> -> groupID</code> <code><has_nonfungible> -> groupType</code> <code>commitment_length, commitment -> subGroup (dropped feature)</code> <code>amount -> groupAmount</code></p> <p>and we worked for months on simplifying group, so we have only 1 groupType and any custom behavior should be done by Script</p> <p>and now this proposal introduces 5 types on the consensus layer...</p> <p>PPS We can have "standard" tokens, a P2SH covenant can require a particular genesis setup, and indexers could scan that one P2SH address and auto-magically add tokens to their database whenever someone spends from the covenant</p> <p>Preview: <a href="https://ide.bitauth.com/import-gist/e81d32df9fa36c4fa961e8065e5a01a1">https://ide.bitauth.com/import-gist/e81d32df9fa36c4fa961e8065e5a01a1</a></p> </div><!-- SC_ON -->   submitted by   <a href="https://www.reddit.com/user/bitcoincashautist"> /u/bitcoincashautist </a> <br/> <span><a href="https://www.reddit.com/r/btc/comments/szdf7c/chip_unforgeable_groups_v60_decentralized/">[link]</a></span>   <span><a href="https://www.reddit.com/r/btc/comments/szdf7c/chip_unforgeable_groups_v60_decentralized/">[comments]</a></span>