Merge pull request bitcoin#604 from commerceblock/master

Adding payment_base to the derivation path as an extra step of security

Author: luke-jr

bip-0175.mediawiki

@@ -74,7 +74,7 @@ Hardened derivation is used at this level.
 
 ===Payment address generation===
 
-For a given contract documents denoted by c<sub>1</sub> ,...,c<sub>n</sub>, payment base extended public key denoted by <code>payment_base</code>, and cryptographic hash function denoted by <code>h</code>.
+For a given contract documents denoted by c<sub>1</sub>,...,c<sub>n</sub>, payment base extended public key denoted by <code>payment_base</code>, and cryptographic hash function denoted by <code>h</code>.
 
 1. Compute cryptographic hashes for all contract documents, by applying the hash function.
 
@@ -84,9 +84,9 @@ For a given contract documents denoted by c<sub>1</sub> ,...,c<sub>n</sub>, paym
 
   hash_1,...,hash_n
 
-3. Concatenate the sorted hashes and apply the hash function.
+3. Prepend payment_base and concatenate the sorted hashes and apply the hash function.
 
-  h(hash_1+...+hash_n)
+  h(payment_base+hash_1+...+hash_n)
 
 4. Compute a partial BIP32 derivation path from the combined hash as defined in Hash to Partial Derivation Path Mapping procedure below.
 
@@ -171,28 +171,28 @@ document 2:
 
 3. Concatenate hashes and apply the hash function.
 
-  concatenated hash:
-  2c26b46b68ffc68ff99b453c1d30413413422d706483bfa0f98a5e886266e7aefcde2b2edba56bf408601fb721fe9b5c338d10ee429ea04fae5511b68fbf8fb9
+  concatenated hash: payment_base
+  xpub6B3JSEWjqm5GgfzcjPwBixxLPzi15pFM3jq4E4yCzXXUFS5MFdXiSdw7b5dbdPGHuc7c1V4zXbbFRtc9G1njMUt9ZvMdGVGYQSQsurD6HAW2c26b46b68ffc68ff99b453c1d30413413422d706483bfa0f98a5e886266e7aefcde2b2edba56bf408601fb721fe9b5c338d10ee429ea04fae5511b68fbf8fb9
   combined hash:
-  ec321de56af3b66fb49e89cfe346562388af387db689165d6f662a3950286a57
+  310057788c6073640dc222466d003411cd5c1cc0bf2803fc6ebbfae03ceb4451
 
 4. Compute the partial BIP32 derivation path of the combined hash.
 
-  60466/7653/27379/46703/46238/35279/58182/22051/34991/14461/46729/5725/28518/10809/20520/27223
+  12544/22392/35936/29540/3522/8774/27904/13329/52572/7360/48936/1020/28347/64224/15595/17489
 
 5. Prepend <code>payment_base</code> to <code>contract_hash</code> derivation path.
 
-  contract_base_pub/60466/7653/27379/46703/46238/35279/58182/22051/34991/14461/46729/5725/28518/10809/20520/27223
+  contract_base_pub/12544/22392/35936/29540/3522/8774/27904/13329/52572/7360/48936/1020/28347/64224/15595/17489
   or
-  m/175'/0'/60466/7653/27379/46703/46238/35279/58182/22051/34991/14461/46729/5725/28518/10809/20520/27223
+  m/175'/0'/12544/22392/35936/29540/3522/8774/27904/13329/52572/7360/48936/1020/28347/64224/15595/17489
 
 6. Compute public extended key.
 
-  xpub6hML7vSU2Hwww9ctwrwt4ijnhJr4n6XaMRox1nnF3PvZKuF1SZoTymnKQHrF9fp2nWJSqv5ZjJSxJJQ8A3PKcBUWhGvTFmuRKpycSCr5coz
+  xpub6hefaATTG5LbcwyPDvmNfnkyzefoM2TJDoo5astH7Gvs1g8vZURviBWvAvBnWc2CNb8ybJ6mDpnQYVsvNSZ3oUmbssX3rUVG97TFYa6AXVk
 
 7. Compute address of the public extended key (P2PKH).
 
-  1HYjhPTtMmpBJBd5tVepZDAVdvPA7o8KHJ
+  1C7f322izqMqLzZzfzkPAjxBzprxDi47Yf
 
 
 ====Verification example (negative test)====
@@ -207,29 +207,33 @@ document 1:
 
   baa5a0964d3320fbc0c6a922140453c8513ea24ab8fd0577034804a967248096
 
-2. Apply the hash function a second time (list of one item).
+2. Prepend payment_base
+
+  xpub6B3JSEWjqm5GgfzcjPwBixxLPzi15pFM3jq4E4yCzXXUFS5MFdXiSdw7b5dbdPGHuc7c1V4zXbbFRtc9G1njMUt9ZvMdGVGYQSQsurD6HAWbaa5a0964d3320fbc0c6a922140453c8513ea24ab8fd0577034804a967248096
+
+2. Apply hash function
 
   3a08605829413ce0bf551b08d21e4a28dbda6e407f90eff1c448e839050c73a1
 
 3. Compute the partial derivation path.
 
-  14856/24664/10561/15584/48981/6920/53790/18984/56282/28224/32656/61425/50248/59449/1292/29601
+  5338/54412/19213/962/30664/62597/11873/59874/56779/24089/54550/19585/28087/36422/18666/17562
 
 4. Prepend contract_base<sub>pub</sub> to contract_hash derivation path.
 
-  contract_base_pub/14856/24664/10561/15584/48981/6920/53790/18984/56282/28224/32656/61425/50248/59449/1292/29601
+  contract_base_pub/5338/54412/19213/962/30664/62597/11873/59874/56779/24089/54550/19585/28087/36422/18666/17562
   or
-  m/175'/0'/14856/24664/10561/15584/48981/6920/53790/18984/56282/28224/32656/61425/50248/59449/1292/29601
+  m/175'/0'/5338/54412/19213/962/30664/62597/11873/59874/56779/24089/54550/19585/28087/36422/18666/17562
 
 5. Compute public extended key.
 
-  xpub6gujKWRhegHXKZBkrprW55oSL6UxYhStxF5FtoUNa4KShLxLPDLQTS39XAwRhdCSvuAv2wogwukmfk3fS7CM6pT6QWwJHiCTw7RkwXMgThy
+  xpub6h9k2KqsMpwghxt7naj1puhGV1ZDC88sxvpYN1HibCf8yQZdPsuhYmmvdK32Kf2Lb3rS1sV8UcZ1f84DJEiXuVfLCAj4bC85aEUCxh38m8i
 
 7. Compute address of the public extended key (P2PKH).
 
-  162KDdRXa3KPgYkH3d1DDKfddacH1gn1n8
+  1QGe5LaDMAmHeibJbZBmZqhQDZSp7QCqSs
 
-8. As expected the address doesn't match the Bitcoin address from the last example <code>1LeYXs63uVSDu2XSb82xdEc7RumohCpB7Q</code>.
+8. As expected the address doesn't match the Bitcoin address from the last example <code>1C7f322izqMqLzZzfzkPAjxBzprxDi47Yf</code>.
 
 Verification operation will succeed only if we use identical documents to ones that have been used in the contract address generation.