{"type":"rich","version":"1.0","author_name":"npub1xvnnyhz8e4eklaakjc9xgm5w8pzkuckt923uacz2cftqdqx23g7q3c5rqg","author_url":"https://nostr.ae/npub1xvnnyhz8e4eklaakjc9xgm5w8pzkuckt923uacz2cftqdqx23g7q3c5rqg","provider_name":"njump","provider_url":"https://nostr.ae","html":"📅 Original date posted:2013-11-02\n📝 Original message:This was one of my concerns when implementing a scheme where you sign a\nrefund transaction before the original transaction is broadcast.  I\noriginally tried to pass a hash and have the server sign it.  However, I\nhad no way to know that what I was signing wasn't a transaction that was\nspending my coins!  So I changed the code to require sending the full\ntransaction, not just the hash.  The other way to mitigate this is through\nnot having any unspent outputs from this key.\n\nFor authentication, you could have both a user-generated and\nserver-generated portion, so that you signed something that clearly had\ndata from you, so even if the server-data was a hash of $EVIL_DOCUMENT, you\nhave clear plausible deniability in that your data that is also signed is\n\"ATTEMPTING LOGIN TO XYZ.COM Hash($EVIL_DOCUMENT)\".\n\n\nOn Sat, Nov 2, 2013 at 4:51 PM, Mark Friedenbach \u003cmark at monetize.io\u003e wrote:\n\n\u003e -----BEGIN PGP SIGNED MESSAGE-----\n\u003e Hash: SHA1\n\u003e\n\u003e Or SIGHASH of a transaction spending those coins or updating the SIN...\n\u003e\n\u003e On 11/2/13 2:14 PM, Johnathan Corgan wrote:\u003e On 11/01/2013 10:01 PM,\n\u003e bitcoingrant at gmx.com wrote:\n\u003e \u003e\n\u003e \u003e\u003e Server provides a token for the client to sign.\n\u003e \u003e\n\u003e \u003e Anyone else concerned about signing an arbitrary string?  Could be\n\u003e \u003e a hash of $EVIL_DOCUMENT, no?  I'd want to XOR the string with my\n\u003e \u003e own randomly generated nonce, sign that, then pass the nonce and\n\u003e \u003e the signature back to the server for verification.\n\u003e \u003e\n\u003e -----BEGIN PGP SIGNATURE-----\n\u003e Version: GnuPG/MacGPG2 v2.0.19 (Darwin)\n\u003e Comment: GPGTools - http://gpgtools.org\n\u003e Comment: Using GnuPG with Thunderbird - http://www.enigmail.net/\n\u003e\n\u003e iQIcBAEBAgAGBQJSdXPaAAoJEAdzVfsmodw4+m8P/1Ce/PwZOYfiFuFJ8pmT2tb2\n\u003e ro7tw7zSr12RSTvs+qRl7lDzJzQ6BDXOdXZCkcU0Vj3TDm8fdrrXN/iw3iQYU/5Y\n\u003e 3K7hj2mGqQUMovCLw0CbrMWrMvor7FhO6MZsRwe0+VxDV/dDrX5f5vSEhnkR26be\n\u003e NrzOFU4hqGM3R4eLq8Bmw5rVD/VCrRzKoXXAvJb1EwM1+fQPjKi+bNMJu3reyfXU\n\u003e 5eMbbiM6tUMmPXy9M6vZrN+6ad53x3KUVP6+/hXxsrnfPp57WQzRZlvwTo/qdJ1C\n\u003e Oxl71m6o2zkXbLTFmg1xmK/A4V1BPTLD6nLDIsw+wTBBfdn22pfDv6Q8d3VRctrd\n\u003e 6x+PMkwysoMjhemmkXCY/7G9GD6AGsrYSqIShSULd9QO5WxAFzRO01ewiRUCUFHi\n\u003e Dn0LEjy8/R/CWK3jvj9uL3vQh9DLdOtqf/X7cEtjF3LThVP+stFTsmXObhTh/8Ai\n\u003e YYjpnwOFG5ZtDzRZfP3OCwyhqlsaMlNgN4xnyR4GPaoJRP3a0zllblIbTWzg6nhY\n\u003e jbON5Ec9N9txGhagYOoAvcQYqGyJdffkBzW82CRUsFYuYYmW2oLUQXPhAGDBIzzj\n\u003e g/7RjMlM1OEp3qctxMZQlrTj7VJmhD768PRLh2XvEDmEC5Qb8Tcq28Nq5t85/O/6\n\u003e i3+pzT5rMuiIZWLx7Msv\n\u003e =tAUY\n\u003e -----END PGP SIGNATURE-----\n\u003e\n\u003e\n\u003e ------------------------------------------------------------------------------\n\u003e Android is increasing in popularity, but the open development platform that\n\u003e developers love is also attractive to malware creators. Download this white\n\u003e paper to learn more about secure code signing practices that can help keep\n\u003e Android apps secure.\n\u003e http://pubads.g.doubleclick.net/gampad/clk?id=65839951\u0026iu=/4140/ostg.clktrk\n\u003e _______________________________________________\n\u003e Bitcoin-development mailing list\n\u003e Bitcoin-development at lists.sourceforge.net\n\u003e https://lists.sourceforge.net/lists/listinfo/bitcoin-development\n\u003e\n-------------- next part --------------\nAn HTML attachment was scrubbed...\nURL: \u003chttp://lists.linuxfoundation.org/pipermail/bitcoin-dev/attachments/20131102/4ee1c42f/attachment.html\u003e"}