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Title: Using Elliptic Curve Calculator (in Armory) - 2-of-2 multisig Question Post by: BeeCoin on May 12, 2013, 06:27:21 PM Hi folks
I was excited to see this post on the Elliptic Curve Calculator in Armory: https://bitcointalk.org/index.php?topic=66862.0 Based on the 2-of-2 Multisig example, I was able to create a shared public key. However, I was not able to get the corresponding shared private key. So, here is the data I have used: Code: 1: Based on this, I've calculated the shared public key in the EC Calculator: Code: ==> PRIVATE 1 * PUBLIC XY 2 (second function): Now, I've tried calculating the shared private key but it didn't match: Code: ==> PRIVATE 1 * 2 (first function): Did I do something wrong? How do I achieve a matching pair of secret public/private keys? -BeeCoin. Title: Re: Using Elliptic Curve Calculator (in Armory) - 2-of-2 multisig Question Post by: BeeCoin on May 27, 2013, 06:36:23 AM Anyone can help me with the calculation? Still not solved...
Title: Re: Using Elliptic Curve Calculator (in Armory) - 2-of-2 multisig Question Post by: jackjack on May 27, 2013, 07:02:35 AM What you do seems ok, do you use the same 'compressedness' for both?
How do you calculate the addresses? Title: Re: Using Elliptic Curve Calculator (in Armory) - 2-of-2 multisig Question Post by: BeeCoin on May 27, 2013, 07:28:33 AM What you do seems ok, do you use the same 'compressedness' for both? That's kind of what I suspect but I wasn't able to put my finger on the problem.How do you calculate the addresses? You can reconstruct the whole calculation using the data in the OP.In Armory Elliptic-Curve Calculator, I've used the second function, called "Scalar Multiply EC Point", using PrivateKey1 and PublicKey2 in X/Y raw form. Title: Re: Using Elliptic Curve Calculator (in Armory) - 2-of-2 multisig Question Post by: jackjack on May 27, 2013, 07:35:59 AM I meant how do you do pubkey->address and privkey->address?
Title: Re: Using Elliptic Curve Calculator (in Armory) - 2-of-2 multisig Question Post by: BeeCoin on May 27, 2013, 08:06:43 AM I meant how do you do pubkey->address and privkey->address? Hi JackJackok... suddenly, problem solved!! I've gone through this at least half a dozen times initially. I don't know what I did different this time - but it works!! Sorry, for taking your time, but I was going crazy... ;) And now it works.. Obviously, PrivateKey1*PublicKey2 vs PublicKey1*PrivateKey2 vs PrivateKey1*PrivateKey2 should result in the same Bitcoin Address for the shared key. And now they do... (see below). thanks again BeeCoin. First step: Create two random private keys (5JvuJuiZiyjFzNqnQ16sbqmQ9wQ26dEaqsbikw734Nega4u2gYN & 5JtTHTXeoq792C7Dy2C7ELEu6RgGQYyQiX2aQ8myWRq4GJnuKj9) Entered them in the "Keys" tab of Armory EC-Calculator in the "Encoded Private Key" section. It was recognized as "Standard base58 key with checksum" and all other keys were generated. Second step: Multiply PrivateKey1 and PublicKey2 Using "Scalar Multiply EC Point" with Raw PrivateKey1 (92b7f1f77f22afd8275cf628e71664082b442202a49eac567e7e7b37ba559e69) and raw X/Y PublicKey2 (X:fa4bb8fe6da6c646ac63361a16a142d6c04269d02fbc740eed2c4a54ba7dda26 // Y:12fec352c07045d144ee96197a68a6060c89eff887ef3f8c2dfea8bff7965f33). Result was: (a*B)x = 68800907c8d450b1c71c9eab88cbb48d7ed7ae33ddd6f92a3553de132214dd56 (a*B)y = 2388823af491f0c105491625eadd7a92add6e6d35926bac0840c17e2254361bc I've entered the result as "Raw public key (x,y)" in the "Keys" section and calculated the Bitcoin address (1BjwqtjfMifRNW6dPdAYyJV7K8dV98Cbmm). Third step: Multiply both private keys. Using "Multiply Scalars (mod n)" I have multiplied both raw private keys (92b7f1f77f22afd8275cf628e71664082b442202a49eac567e7e7b37ba559e69 and 8d288fef6dfed2edffb34f620256975fe9dbe2949f7e61b14b91d0be593d628a). The result is a shared private key (31ac197e32af979fc9010b39b7a3c84358d9bfb669f59562b4a63fc86a8bf754). In the "Keys" section, using the calculated raw private key, I've calculated the Bitcoin address (1BjwqtjfMifRNW6dPdAYyJV7K8dV98Cbmm). And yes... it matches!!! |