Create CHANGELOG

CHANGELOG

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+## History:  
+
+### Current Build (Pending release date)
+- Upgrade to Protocol 5 (Hard fork)
+- Implementation of PIP-0032 (Atomic Swaps) -> https://github.com/PascalCoin/PascalCoin/blob/master/PIP/PIP-0032.md
+- Implementation of PIP-0030 (Safebox root) -> https://github.com/PascalCoin/PascalCoin/blob/master/PIP/PIP-0030.md
+- Implementation of PIP-0029 (Account Seals) -> https://github.com/PascalCoin/PascalCoin/blob/master/PIP/PIP-0029.md
+- Implementation of PIP-0024 (Account Data) -> https://github.com/PascalCoin/PascalCoin/blob/master/PIP/PIP-0024.md
+- Implementation of PIP-0033 (OpData JOSN-RPC calls) -> https://github.com/PascalCoin/PascalCoin/blob/master/PIP/PIP-0033.md
+- Partial implementation of PIP-0012 (Recover Accounts option after 4 years) -> https://github.com/PascalCoin/PascalCoin/blob/master/PIP/PIP-0012.md
+- Updated "OP_DATA" operation: (PIP-0016)
+  - New digest hash value for OP_DATA ( PIP-0016 ) on Protocol 5
+  - Added "id" field (GUID/UUID type as described on PIP-0016), was missing on V4, added on V5
+- Updated "OP_CHANGE_ACCOUNT_INFO" and "OP_MULTIOPERATION" to allow Account.Data as described on PIP-0024
+  - Added "new_data" field allowing update Account.Data field (0..32 bytes)
+  - Updated digest hash value adding "new_data" field  
+- Hardcoded RandomHash digest/hash values for quick speed safebox check on fresh installation
+- JSON-RPC changes:  
+  - Updated "listaccountforsale" method to allow ATOMIC SWAPS (PIP-0032)
+    - Added "type" to discrimine between kind of listing. Available values are:
+      - "public_sale"
+      - "private_sale": Need to provide a valid "new_enc_pubkey" or "new_b58_pubkey"
+      - "atomic_account_swap": Need to provide a valid "new_enc_pubkey" or "new_b58_pubkey" and the unlocking param "enc_hash_lock"
+      - "atomic_coin_swap": Need to provide a valid "enc_hash_lock"
+      - If no "type" is defined, will automatically select between "public_sale" or "private_sale"
+    - Added "enc_hash_lock" (HEXASTRING) that must be exactly a 32 bytes value (stored as 64 bytes because is HexaString)
+  - Updated "changeaccountinfo" and "signchangeaccountinfo" calls to allow add "new_data" field for change Account.Data value (PIP-0024)
+    - New param "new_data" (HEXASTRING) if provided will change Account Data info. Limited from 0 to 32 bytes.
+  - New method "senddata" as described on PIP-0033 returning an "Operation Object"
+  - New method "signdata" as described on PIP-0033 returning a "Raw Operations Object"
+  - New method "finddataoperations" as described on PIP-0033 returning an ARRAY of "Raw Operations Object"
+    - News params added to original PIP
+      - "depth" (Integer, 1000 by default) : Will search backward in blocks a maximum of "depth" blocks
+      - "startblock" (Integer, optional) : If defined, will start at a specified block, otherwise will start at last "sender" or "target" updated block
+  - Updated "Account Object" return values:
+    - "state": Can return "normal", "listed", "account_swap", "coin_swap"
+    - "hashed_secret" : (HEXASTRING) will contain the SHA256( SECRET ) value that must match Payload received data for Atomic Swaps (only when "state" in "account_swap" or "coin_swap")
+    - "amount_to_swap" : (PASCURRENCY) amount that will be transferred to counterparty account on ATOMIC COIN SWAP ("receiver_swap_account")
+    - "receiver_swap_account": (Integer) Counterpaty account that will receive "amount_to_swap" on ATOMIC COIN SWAP
+    - "data" : (HEXASTRING) will return the Account Data stored with PIP-0024
+    - "seal" : (HEXASTRING) will return the Account Seal stored with PIP-0029
+  - Updated "Operation Object" return values:
+    - "senders" : ARRAY
+      - "data" : OBJECT will store OP_DATA information when operation is OP_DATA type as described on PIP-0016
+        - "id" : (String) String representation of GUID/UUID as "00000000-0000-0000-0000-000000000000" that stores 16 bytes
+        - "sequence" : (Integer)
+        - "type" : (Integer)
+    - "changers" : ARRAY
+      - "new_data" : (HEXASTRING) : If "data" is changed on "account"
+      - "changes" : (String) Description of changes type made
+  - Updated "Multi Operation Object" values:
+    - "changers" : ARRAY
+      - "new_data" : (HEXASTRING) : If "data" is changed on "account"
+
+TODO  
+- TODO: RPC calls for PIP-0029
+- TODO: RPC calls for PIP-0030
+- TODO: RPC calls for PIP-0016
+
+### Build 4.1.0.0 - 2019-07-24
+- Hardcoded RandomHash digest/hash values for quick speed safebox check on fresh installation
+  - GUI wallets will load "HardcodedRH_75800.randomhash" file (at exe folder) and preload a randomhash digest/hash values for quick first time synchronization
+- Fixed bug caused by CT_NetOp_GetSafeBox too quickly on old versions (4.0.2 and lower)
+  - Added a delay of at least 1 second per call when peer node is protocol version lower than version 9
+- Fixed bug #187 found by Isaac Cook (icook)
+- Improved memory management on NetProtection (auto clean memory)
+
+### Build 4.0.3.1 - 2019-04-12
+- Fixed core bug #182 in RPC calls
+
+### Build 4.0.3 - 2019-04-10
+- Improvements:
+  - Up to +1600 operations per second using a domestic computer (4 CPU)
+  - Download and check new Safebox in less than 5 minutes
+- TESTNET:
+  - Added functions to automatically receive new accounts for new installed fresh nodes
+- Major refactoring: 
+  - Change TRawBytes from "AnsiString" to "TBytes" type
+  - Do not use AnsiString type for simple string types, use String instead
+  - Usage of TList<T> type
+  - Allow compilation using Delphi 10.2 and multidevice (Firemonkey)
+- Core features
+  - Added CryptoLib4Pascal library that will allow to replace OpenSSL in a future for a Pascal pure native cryptographic suite (for testing purposes at this moment, not actived by default)
+  - Important log reduction
+  - Adding multithreading validation
+    - Multithreading validating Signatures
+    - Multithreading validating Blocks headers (TOperationBlock)
+- Fixed core bugs:
+  - Miner bug after loading blocks on start-up if last saved block was a checkpoint block
+- Gui-Classic
+  - Multithread on User Accounts to avoid freeze when updating data
+  - Fixed Minor bugs (See GitHub commits since 2019-01-08)  
+
+### Build 4.0.2 - 2019-01-08
+- Improvement speed (high performance): checking valid signature only once if operation is on mempool and was verified previously
+- Improved operations/blocks propagation
+- Fixed a decompression bug caused by FreePascal "paszlib" package bug on version 3.0.4 -> https://bugs.freepascal.org/view.php?id=34422
+- Allow download new safebox (instead of download pending blocks) when difference > TNode.MinFutureBlocksToDownloadNewSafebox
+  - 7 days by default for Production, 1 for Testnet
+  - Disabled by default on Daemon, configure on INI file with MINPENDINGBLOCKSTODOWNLOADCHECKPOINT
+  - Enabled by default on GUI, can configure it
+  - Will not delete current blockchain, but will not download pending blocks between last block saved and current network checkpoint block
+- Allow only connections using Net protocol >= 9  (Introduced on Build 4.0.1)
+- Fill automatic params at "buyaccount" RPC call: Will set 'price' and 'seller_account' values to current safebox values if not provided
+- Improved memory usage on mempool operations (TPCOperationsStorage)
+- Important logs reduction to store only logs that are important
+- Fixed minor bugs and minor improvements (See GitHub commits since 2018-10-31)
+
+### Build 4.0.1 - 2018-10-31
+- Fixed a critical "Access violation" at "Fast Block Propagation" process
+- Fixed a critical "Access violation" at "Get blockchain operations" process
+- Fixed a memory leak at "Get Block operations"
+- Updated Net protocol available to 9 (8 was introduced at build 4.0.0)
+
+### Build 4.0.0 - 2018-10-26
+- MANDATORY UPGRADE - HARD FORK ACTIVATION WILL OCCUR ON BLOCK 260000
+  - PIP - 0009: RandomHash
+    - RandomHash is a new hash algo created by Herman Schoenfeld, see https://github.com/PascalCoin/PascalCoin/blob/master/PIP/PIP-0009.md 
+  - PIP - 0015: Fast Block Propagation
+  - PIP - 0016: Layer-2 protocol support 
+  - Critical bug fix: New digest hash for signature verifications
+  - Limit blockchain to allow max only one 0-fee operation by signer per block (prior was limited by network, not by core)  
+  - Added OrderedAccountKeysList that allows an indexed search of public keys in the safebox with mem optimization
+  - Improved net protections
+- JSON-RPC changes:
+  - New protection for "open ports" server: When a server has whitelist to ALL IP's access to JSON-RPC calls, all calls that use the wallet keys are protected to avoid hacking
+    - Added param "RPC_ALLOWUSEPRIVATEKEYS" on pascalcoin_daemon.ini file
+  - New params for "findaccounts":
+    - "exact" (Boolean, True by default): Only apply when "name" param has value, will return exact match or not
+    - "listed" (Boolean, False by default): Will return only listed for sale accounts
+    - "min_balance","max_balance" (PASCURRENCY): Filter by balance
+	- "enc_pubkey" or "b58_pubkey": If provided will search accounts with this pubkey. In this case the "start" param value is the position of indexed public keys list instead of accounts numbers
+  - New return param in "Multioperation Object"
+    - "digest" (HEXASTRING): Returns the digest value that must be signed
+  - New param for "multioperationsignoffline"
+    - "protocol" (Integer): Must provide protocol version. By default will use build protocol constant CT_BUILD_PROTOCOL
+  - New param for "signsendto"
+    - "protocol" (Integer): Must provide protocol version. By default will use build protocol constant CT_BUILD_PROTOCOL
+  - New param for "signchangekey"
+    - "protocol" (Integer): Must provide protocol version. By default will use build protocol constant CT_BUILD_PROTOCOL
+  - New param for "signlistaccountforsale"
+    - "protocol" (Integer): Must provide protocol version. By default will use build protocol constant CT_BUILD_PROTOCOL
+  - New param for "signdelistaccountforsale"
+    - "protocol" (Integer): Must provide protocol version. By default will use build protocol constant CT_BUILD_PROTOCOL
+  - New param for "signchangeaccountinfo"
+    - "protocol" (Integer): Must provide protocol version. By default will use build protocol constant CT_BUILD_PROTOCOL
+  - New param for "signbuyaccount"
+    - "protocol" (Integer): Must provide protocol version. By default will use build protocol constant CT_BUILD_PROTOCOL
+  - Account Object change:
+    - Changed return value of "price". Previously was returned without decimals in native value (inconsistency bug), now will be returned as a PASCURRENCY (with 4 decimals)
+- Bug fixed: DoProcess_GetAccount_Request request type=1 (single account) didn't returned only 1
+- Bug fixed: Invalid "lastBlockCache" value when found and orphan block that causes invalid propagation until a new block is found. Fixed.
+- Bug fixed: "Access violation" on "getpendings" JSON-RPC call when pendings count>0
+- Net protocol upgraded to "8" in order to accept new network p2p calls:
+  - "Fast block propagation" : NetOp 0x0012 for PIP-0015 
+  - "Get blockchain operations": NetOp 0x0013 for PIP-0015
+  - "Get Public key accounts": NetOp 0x0032
+
+### Build 3.0.1 - 2018-05-07
+- Deprecated use of OpenSSL v1.0 versions. Only allowed OpenSSL v1.1 versions
+- JSON-RPC Added param "openssl" on "nodestatus" call. Will return OpenSSL library version as described in OpenSSL_version_num ( https://www.openssl.org/docs/man1.1.0/crypto/OPENSSL_VERSION_NUMBER.html )
+
+### Build 3.0.0 - 2018-05-02
+- Implementation of Hard fork on block 210000
+  - PIP - 0010: 50% inflation reduction
+  - PIP - 0011: 20% Development reward
+  - PIP - 0017: Anonymity via transaction mixing (multioperation)
+  - New target calc on protocol V3 in order to reduce the sinusoidal effect
+    - Harmonization of the sinusoidal effect modifying the rise / fall by 50% calculating over the last 10 blocks only when increase/decrease is high
+- New Safebox Snapshoting
+  - This allow quickly rollback/commit directly to Safebox instead of create a separate Safebox on memory (read from disk... use more ram...)
+  - Is usefull when detecting posible orphan blocks in order to check which chain is the highest chain without duplicating a safebox to compare
+- New Node network operations
+  - Get pending operations (code $0030)
+    - Implementation of the PIP-0013 (not exactly but with similar features)	
+  - Get account (code $0031)
+    - This call will allow a simple third party app communicate directly to a node to get account info (balance, n_operation, name, public key... )
+  - Reserverd codes from $1000 to $1FFF
+    - A node will not break connection if those codes are used, but will response with ERRORCODE_NOT_IMPLEMENTED ($00FF)
+- MultiOperation: PIP-0017
+  - Multioperation allows a transactional like operations, they can include transactions and change info operations in a signle multioperation
+    - Allow to send coins from N accounts to M receivers in a transaction mixing, without knowledge of how many coins where sent from "Alice" to "Bob" if properly mixed
+	- Ophash can be previously known by all signers before signing. They must sign only if multioperation includes it's transactions as expected 
+	- OpHash of a multioperation will allow to include n_operation and account of each signer account, but md160hash chunk will be the same for all
+- JSON-RPC changes:
+  - Added param "startblock" to "getaccountoperations" in order to start searching backwards on a specific block. Note: Balance will not be returned on each operation due cannot be calculated. Default value "0" means start searching on current block as usual
+  - Operation Object changes:
+    New fields:
+    - "senders" : ARRAY of objects - When is a transaction, this array contains each sender
+      - "account" : Sending Account 
+      - "n_operation"
+      - "amount" : PASCURRENCY - In negative value, due it's outgoing from "account"
+      - "payload" : HEXASTRING
+    - "receivers" : ARRAY of objects - When is a transaction, this array contains each receiver
+      - "account" : Receiving Account 
+      - "amount" : PASCURRENCY - In positive value, due it's incoming from a sender to "account"
+      - "payload" : HEXASTRING
+    - "changers" : ARRAY of objects - When accounts changed state
+      - "account" : changing Account 
+      - "n_operation"
+      - "new_enc_pubkey" : If public key is changed or when is listed for a private sale
+      - "new_name" : If name is changed
+      - "new_type" : If type is changed
+      - "seller_account" : If is listed for sale (public or private) will show seller account
+      - "account_price"	: PASCURRENCY - If is listed for sale (public or private) will show account price
+      - "locked_until_block" : If is listed for private sale will show block locked
+      - "fee" : PASCURRENCY - In negative value, due it's outgoing from "account"
+    Modified fields / DEPRECATED FIELDS
+    Caused by multioperation introduction, search in "senders"/"receivers"/"changers" instead
+    - "balance" will not be included when is not possible to calc previous balance of account searching at the past
+    - "signer_account" will not be included in Multioperations
+    - "account" : will not be included in Multioperations, use fields in "senders"/"receivers"/"changers" instead    
+    - "n_operation" will not be included in Multioperations, use fields in "senders"/"receivers"/"changers" instead
+    - "payload" will not be included in Multioperations, use fields in "senders"/"receivers"/"changers" instead
+    - "sender_account" is not correct to be used. Use "account" param on "senders" array instead
+    - "dest_account" is not correct to be used. Use "account" param on "receivers" array instead
+    - "amount" is not correct to be used. Use each "amount" param on "senders/receivers" instad. Note: sender "amount" is a negative number, positive for receiver
+  - New object "MultiOperation Object" : Will return info about a MultiOperation
+    - "rawoperations" : HEXASTRING with this single MultiOperation in RAW format
+    - "senders" : Will return an Array with Objects
+      - "account" : Sending Account 
+      - "n_operation"
+      - "amount" : In negative value, due it's outgoing from "account"
+      - "payload"
+    - "receivers"
+      - "account" : Receiving Account 
+      - "amount" : In positive value, due it's incoming from a sender to "account"
+      - "payload"
+    - "changers" : Will return an Array with Objects
+      - "account" : changing Account 
+      - "n_operation"
+      - "new_enc_pubkey" : If public key is changed
+      - "new_name" : If name is changed
+      - "new_type" : If type is changed
+    - "amount" : PASCURRENCY Amount received by receivers
+    - "fee" : PASCURRENCY Equal to "total send" - "total received"
+	- "signed_count" : Integer with info about how many accounts are signed. Does not check if signature is valid for a multioperation not included in blockchain 
+	- "not_signed_count" : Integer with info about how many accounts are pending to be signed
+    - "signed_can_execute"	: Boolean. True if everybody signed. Does not check if MultiOperation is well formed or can be added to Network because is an offline call
+  - New method "signmessage": Signs a digest message using a public key
+    - Params:
+      - "digest" : HEXASTRING with the message to sign
+	  - "b58_pubkey" or "enc_pubkey" : HEXASTRING with the public key that will use to sign "digest" data
+    - Result: False on error
+      - "digest" : HEXASTRING with the message to sign
+	  - "enc_pubkey" : HESATRING with the public key that used to sign "digest" data
+	  - "signature" : HEXASTRING with signature
+  - New method "verifysign": Verify if a digest message is signed by a public key
+    - Params:
+      - "digest" : HEXASTRING with the message to check
+	  - "b58_pubkey" or "enc_pubkey" : HEXASTRING with the public key that used to sign "digest" data
+	  - "signature" : HEXASTRING returned by "signmessage" call
+    - Result: False on error
+      - "digest" : HEXASTRING with the message to check
+	  - "enc_pubkey" : HESATRING with the public key that used to sign "digest" data
+	  - "signature" : HEXASTRING with signature
+  - New method "multioperationaddoperation": Adds operations to a multioperation (or creates a new multioperation and adds new operations)
+    This method does not need current Safebox state, so can be used offline or on COLD wallets when all info is provided
+    - Params:
+      - "rawoperations" : HEXASTRING (optional) with previous multioperation. If is valid and contains a single  multiopertion will add operations to this one, otherwise will generate a NEW MULTIOPERATION
+	  - "auto_n_operation" : Boolean - Will fill n_operation (if not provided). Only valid if wallet is ONLINE (no cold wallets)
+      - "senders" : ARRAY of objects that will be Senders of the multioperation
+        - "account" : Integer
+        - "n_operation" : Integer (optional) - if not provided, will use current safebox n_operation+1 value (on online wallets)
+        - "amount" : PASCURRENCY in positive format
+        - "payload" : HEXASTRING
+      - "receivers" : ARRAY of objects that will be Receivers of the multioperation
+        - "account" : Integer
+        - "amount" : PASCURRENCY in positive format
+        - "payload" : HEXASTRING
+      - "changesinfo" : ARRAY of objects that will be accounts executing a changing info
+        - "account" : Integer
+        - "n_operation" : Integer (optional) - if not provided, will use current safebox n_operation+1 value (on online wallets)
+        - "new_b58_pubkey"/"new_enc_pubkey": (optional) If provided will update Public key of "account"
+        - "new_name" : STRING (optional) If provided will change account name
+        - "new_type" : Integer (optional) If provided will change account type
+    - Result:
+      If success will return a "MultiOperation Object"
+  - New method "multioperationsignoffline"
+    This method will sign a Multioperation found in a "rawoperations"
+	Must provide info about accounts and keys (current Safebox state, provided by an ONLINE wallet)
+    - Params:
+      -	"rawoperations" : HEXASTRING with 1 multioperation in Raw format
+      - "accounts_and_keys"	: ARRAY of objects with info about accounts and public keys to sign
+        - "account" : Integer 
+        - "b58_pubkey" or "enc_pubkey" : HEXASTRING with the public key of the account
+    - Result:
+      If success will return a "MultiOperation Object"
+  - New method "multioperationsignonline"
+    This method will sign a Multioperation found in a "rawoperations" based on current safebox state public keys
+	Must provide info about accounts and keys (current Safebox state, provided by an ONLINE wallet)
+    - Params:
+      -	"rawoperations" : HEXASTRING with 1 multioperation in Raw format
+    - Result:
+      If success will return a "MultiOperation Object"
+  - New method "operationsdelete"
+    This method will delete an operation included in a Raw operations object
+    - Params:
+      -	"rawoperations" : HEXASTRING with Raw Operations Object
+    - Result:
+      If success will return a "Raw Operations Object"
+      - "rawoperations" : HEXASTRING with operations in Raw format
+      - "operations" : Integer
+      - "amount" : PASCURRENCY
+      - "fee" : PASCURRENCY  
+  - Updated method "getpendings" : Added params "start" (0..N) default=0 and "max" default=100 (0 = ALL)
+    - Also fixed bug #86 : https://github.com/PascalCoin/PascalCoin/issues/86
+  - New method "getpendingscount" : Returns pending operations count
+- Daemon:
+  - Allow to force max block read from Blockchain when started using "-b MAX_BLOCK_NUMBER" param. Example "nohup ./pascalcoin_daemon -r -b 12345 &"
+- Protections against invalid nodes (scammers):
+  - Protection on GetBlocks and GetBlockOperations
+- Merged new GUI with current stable core
+- New folders organization
+- Bugs solved
+
+### Build 2.1.9 - 2018-04-16
+- Searchs last valid block found on corrupted BlockChainStream.blocks file and allows to continue from last valid one. On prior versions, app halted and needed manually file deletion
+
+### Build 2.1.8 - 2018-04-16
+- Solved bug that can cause to corrupt BlockChainStream.blocks file when detecting an orphan block and creating new BlockHeaders row (every 1000 blocks). Very rare bug, but fatal error
+
+### Build 2.1.7 - 2018-04-10
+- Remove use of TPCOperation.FSignatureChecked introduced on 2.1.6 because is not 100% secure
+- Minor bugs
+
+### Build 2.1.6 - 2018-02-14
+- Important improvements
+  - Improved speed when processing operations on start
+  - Improved speed when processing pending operations after a new block found
+  - Deleted duplicate "SanitizeOperations" call
+  - Verify signed operations only once (TPCOperation.FSignatureChecked Boolean)
+  - Improvements in search methods of TOperationsHashTree
+    - Increase speed in search methods thanks to internal ordered lists
+    - Increase speed copying thanks to using FHashTree sender buffer instad of generating new one
+  - Internal bugs
+- Those improvements solved BUG that caused operations not included to blockchain due slow processing with MemPool 
+- NOTE: It's HIGHLY RECOMMENDED to upgrade to this version
+
+### Build 2.1.5 - 2018-02-09
+- GUI changes:
+  - Allow massive accounts "change info" operation
+  - Added "account type" and "sale price" on accounts grid
+  - Show "account type" stats on search account form  
+  - Changed Icon to current PascalCoin icon
+- Pending operations buffer cached to file to allow daemon/app restart without losing pending operations
+- Less memory usage thanks to a Public keys centralised buffer
+- JSON-RPC changes
+  - Added param "n_operation" to "Operation Object" JSON-RPC call
+  - New method "findnoperation": Search an operation made to an account based on n_operation field
+    - Params:
+	  - "account" : Account
+	  - "n_operation" : n_operation field (n_operation is an incremental value to protect double spend)
+	- Result:
+	  - If success, returns an Operation Object	  
+  - New method "findnoperations": Search an operation made to an account based on n_operation 
+    - Params:
+	  - "account" : Account
+	  - "n_operation_min" : Min n_operation to search
+	  - "n_operation_max" : Max n_operation to search
+	  - "start_block" : (optional) Block number to start search. 0=Search all, including pending operations
+	- Result:
+	  - If success, returns an array of Operation Object
+  - New method "decodeophash": Decodes block/account/n_operation info of a 32 bytes ophash
+    - Params:
+      - "ophash" : HEXASTRING with an ophash (ophash is 32 bytes, so must be 64 hexa valid chars)
+    - Result:
+      - "block" : Integer. Block number. 0=unknown or pending
+      - "account" : Integer. Account number
+      - "n_operation" : Integer. n_operation used by the account. n_operation is an incremental value, cannot be used twice on same account.
+      - "md160hash" : HEXASTRING with MD160 hash
+- Solved bug that caused to delete blockchain when checking memory 
+- Solved bug in Network adjusted time on receiving connections caused by full entry buffer
+- Minor optimizations
+
+### Build 2.1.3.0 - 2017-11-15
+- Fixed BUG when buying account assigning an invalid public key
+- Added maxim value to node servers buffer, deleting old node servers not used, this improves speed
+- Re-add orphaned operations back into the pending pool
+- RPC locking to prevent N_Operation race-condition on concurrent invocations
+- Minor bugs
+
+### Build 2.1.2.0 - 2017-07-27
+- No more blockchain in installer = TRUE DELETABLE BLOCKCHAIN (Safebox will be automatically downloaded by client from network)
+- Fixed storage bug when downloading a new safebox
+- Safebox will be downloaded in small chunks (aprox 2mb per chunk)
+- Read safebox file improvements (quick start)
+
+### Build 2.1.1.0 - 2017-07-16
+- Fixed installer bug: In last Windows installer a malformed safebox file was included. This build is only to provide a good safebox file with the installer
+- No important changes in exe/binary file 
+
+### Build 2.1.0.0 - 2017-07-14
+- Fixed bug of slow mass transactions from a single account due to incorrect sending order
+- Fixed memory leak on GetSafeBox request call
+- Added new GUI improvements on Operations form
+
+### Build 2.0.0.0 - 2017-06-23
+- MANDATORY UPGRADE - HARD FORK ACTIVATION WILL OCCUR ON BLOCK 115000
+- Introducing Protocol v2.
+  - https://github.com/PascalCoin/PascalCoin/blob/master/PascalCoinWhitePaperV2.pdf
+  - Core Changes:
+    - New safebox hash calculation algorithm to allow safebox checkpointing
+    - Improved difficulty target calculation to obtain a more stable average blocktime of 5 minutes, given abrupt hashpower fluctuations
+    - Bug-fix for China region users
+    - Anti-spam measures
+      - New Consensus Rule: A block can only contain 1 zero fee operation per sender account. If a sender account issues 2 or more zero-fee operations, that block is invalid.
+    - SafeBox now stored in chunks to facilitate checkpoint distribution
+	- Reintroduce orphan blocks operations on main blockchain
+  - Added Checkpointing:
+    - Checkpoint created on every 100'th block
+    - Added network operations to transfer Checkpoint chunks (compressed)
+  - Addded In-Protocol PASA Exchanging:
+    - New Operation: List Account, used to list an account for public or private sale 
+    - New Operation: Delist Account, used to delist an account from sale 
+    - New Operation: Buy Account, used to purchase an account lised for sale
+    - Updated Operation: Transaction, can be used in place of Buy Account operation in private account sales
+  - RPC API Changes:
+    - All changes are backwards-compatible for current 3rd-party infrastructure providers (exchanges, wallets).
+    - However, use of param "ophash" has been changed in V2, see "Operation Object changes" section to know how to use "old_ophash" param value    
+    - JSON changes:
+      - Account Object changes:
+        - Added param "state"  (values can be "normal" or "listed". When listed then account is for sale)
+        - If "state" is "listed" then will fill next values:
+          - "locked_until_block", "price", "seller_account" 
+          - "private_sale" : Boolean value 
+          - "new_enc_pubkey" : (Only on "private_sale" = true) - HEXASTRING with private sale encoded public key
+        - Added param "name": String
+          - Name available chars: abcdefghijklmnopqrstuvwxyz0123456789!@#$%^&*()-+{}[]\_:"|<>,.?/~
+          - Name first char: (cannot start with number): abcdefghijklmnopqrstuvwxyz!@#$%^&*()-+{}[]\_:"|<>,.?/~
+          - Name lenght: Empty or 3..64 chars length
+        - Added param "type": Integer (Valid values from 0..65535)
+      - Operation Object changes:
+        - Changed param "ophash": Current returned value of "ophash" is not the same than previous builds (changed calculation method)
+        - New param "old_ophash": Will return previous "ophash" value only for old blocks (prior to v2 protocol activation)
+        - New param "subtype" : Based on "optype" param, this param allows to discrimine point of view of operation (sender/receiver/buyer/seller ...)
+        - New param "signer_account" : Will return the account that signed (and payed fee) for this operation
+        - Param "enc_pubkey": Will return both change key and the private sale public key value
+        - About method "findoperation" and "ophash"
+          - Due to changed "ophash" param value calculation, method "findoperation" will find old "ophash" values too
+          - This is to avoid 100% compatibility, but remember that returned "Operation object" will contain "ophash" value calculated in new format only (you can read "old_ophash" value in older blocks)
+      - New methods:
+        - "listaccountforsale" : Lists an account for sale (public or private)
+          - Params:
+            - "account_target" : Account to be listed
+            - "account_signer" : Account that signs and pays the fee (must have same public key that listed account, or be the same)
+            - "price": price account can be purchased for
+            - "seller_account" : Account that will receive "price" amount on sell
+            - "new_b58_pubkey"/"new_enc_pubkey": If used, then will be a private sale
+            - "locked_until_block" : Block number until this account will be locked (a locked account cannot execute operations while locked)
+            - "fee","payload","payload_method","pwd"
+        - "signlistaccountforsale" : Signs a List an account for sale (public or private) for cold wallets
+          - Params: Same "listaccountforsale" params, and also:
+            - "rawoperations" : HEXASTRING with previous signed operations (optional)
+            - "signer_b58_pubkey"/"signer_enc_pubkey" : The current public key of "account_signer"
+            - "last_n_operation" : The current n_operation of signer account        
+        - "delistaccountforsale" : Delist an account for sale
+          - Params:
+            - "account_target" : Account to be delisted
+            - "account_signer" : Account that signs and pays the fee (must have same public key that delisted account, or be the same)
+            - "fee","payload","payload_method","pwd"
+        - "signdelistaccountforsale" : Signs a List an account for sale (public or private) for cold wallets
+		  - Params: Same "delistaccountforsale" params, and also:
+            - "rawoperations" : HEXASTRING with previous signed operations (optional)
+            - "signer_b58_pubkey"/"signer_enc_pubkey" : The current public key of "account_signer"
+            - "last_n_operation" : The current n_operation of signer account                      
+        - "buyaccount" : Buy an account previously listed for sale (public or private)
+          - Params: 
+            - "buyer_account","account_to_purchase",
+            - "price","seller_account",
+            - "new_b58_pubkey"/"new_enc_pubkey","amount",
+            - "fee","payload","payload_method","pwd"
+        - "signbuyaccount" : Signs a buy operation for cold wallets
+          - Params: Same "buyaccount" params, and also:
+            - "rawoperations" : HEXASTRING with previous signed operations (optional)
+            - "signer_b58_pubkey"/"signer_enc_pubkey" : The current public key of "buyer_account"
+            - "last_n_operation" : The current n_operation of buyer account	
+        - "changeaccountinfo" : Changes an account Public key, or name, or type value (at least 1 on 3)
+            - Params:
+            - "account_target" : Account to be delisted
+            - "account_signer" : Account that signs and pays the fee (must have same public key that target account, or be the same)
+            - "new_b58_pubkey"/"new_enc_pubkey": If used, then will change the target account public key
+            - "new_name": If used, then will change the target account name
+            - "new_type": If used, then will change the target account type
+            - "fee","payload","payload_method","pwd"
+        - "signchangeaccountinfo" : Signs a change account info for cold cold wallets
+          - Params: Same "changeaccountinfo" params, and also:
+            - "rawoperations" : HEXASTRING with previous signed operations (optional)
+            - "signer_b58_pubkey"/"signer_enc_pubkey" : The current public key of "account_signer"
+            - "last_n_operation" : The current n_operation of signer account
+        - "findaccounts" : Find accounts by name/type and returns them as an array of Account objects
+          - Returned array will be sorted by account number
+          - Params:
+            - "name" : (String) If has value, will return the account that match name
+            - "type" : (Integer) If has value, will return accounts with same type
+            - "start" : (Integer) Start account (by default, 0)
+            - "max" : (Integer) Max of accounts returned in array (by default, 100)
+      - Updated methods:
+        - "changekey" : Added param "account_signer" that allow to pay fee using another account with same public key than target "account" param. This allows to change keys on empty accounts (balance = 0) and pay fee
+        - "signchangekey" : Added param "account_signer", same use that in "changekey" method
+  - GUI changes:  (not available on daemon)
+    - New columns "name" and "type" on accounts
+    - Information about Accounts/Operation using F1
+    - Operations form now accepts:  (Will be active after V2 protocol activation)
+      - List account for sale (public or private)
+      - Delist account
+      - Buy account
+      - Change account name/type
+    - Operations form allows to search for accounts using F2 over an account edit box
+    - Changes in text showing operations information     
+- Other changes:
+  - Bug for china users fixed  
+  - Bugs fixed
+
+### Build 1.5.6.0 - 2017-05-03
+- Allow multiselect accounts (GUI wallet)
+- Priority for operations with fee:
+  - Allow miner server (pools) to select what to mine using pascalcoin_daemon.ini file (daemon only)
+    - RPC_SERVERMINER_MAX_OPERATIONS_PER_BLOCK: Max of operations that can be included in a block (Default 5000, min value 1000)
+    - RPC_SERVERMINER_MAX_ZERO_FEE_OPERATIONS: Max of operations with 0 fee that can be included in a block (Default 2000, min value 400)
+  - Operations with fee have always preference over 0 fee operations (will be mined first)
+  - If operations with fee fills all the buffer, then no zero fee operation will be included
+- Fixed bug on receiving big blocks and slow net connection to prevent never synchronize
+- Fixed bug on miner server that produces "invalid operations hash" error on valid solutions with 0 operations
+- Fixed bug on file storage
+- Fixed minor bugs
+
+### Build 1.5.5.0 - 2017-04-11
+- Corrected fee result on RPC calls as a negative number on "Change key" operations
+- Corrected PASCURRENCY value to be limited as a 4 decimal digits on RPC calls
+- JSON-RPC method "getaccountoperations" changed: if param "start" is -1, will include pending operations, otherwise not
+- Fixed bug: On "getaccountoperations" if an account had a lot of operations (receive tx included) then sometimes app crashed when executing depth search.
+  - Note: High depth search is slow because it search always starting from current state, going backwards, in order to return past balance. This can be a slow method on some account with high transactions volume.
+
+### Build 1.5.4.0 - 2017-03-14
+
+- Added Network Timestamp Adjustment (NAT) to calc valid timestamps
+  - Minimum 4 active connections to calc median used for NAT, otherwise use local timestamp
+  - Based on IP's (to prevent a malicious IP timejacking, each IP is only used once)
+  - Removed IP's and recalculated after disconnecting (to prevent malicious node connecting/disconnecting for timejacking)
+- New blocks will not be accepted if using future timestamp greater than NAT timestamp + 15 seconds (also, mantaining current protocol rule >= lastBlock.timestamp)
+- Network protocol fixed to 5-5 (Nodes with version prior to 1.5 will not be allowed)
+- Added protection for non included operations on a block, to prevent continuous sending. Only will resend operations once.
+- Bug #27 fixed: Invalid timestamp on FPC (https://github.com/PascalCoin/PascalCoin/issues/27)
+- JSON-RPC
+  - Method "getconnections" added "timediff" to know timestamp diff of node
+  - Method "payloaddecrypt" added "unenc_hexpayload" result value with HEXASTRING of unencrypted payload
+- Fixed some "Random Memory access violation errors" bugs found caused by multithreading and disconnected nodes
+
+### Build 1.5.3.0 - 2017-03-06
+
+- Fixed issue #23: RPC findoperation fails to find operation by opHash
+- Miners best practices: Sending new job with new timestamp every 30 seconds
+- Buffering last 10 sent jobs to miners
+- Small delay prior to destroy a connection to prevent exception handling
+- Minor logs changes
+
+
+### Build 1.5.2.0 - 2017-03-03
+
+- Added a jobs buffer for miners. This will allow to submit old job solutions (limited buffer). (Fix the "tx" issue)
+- Miner jobs will not be sent every time a transaction is received, thet will be buffered and sent every few seconds (Fix the "tx" issue)
+- Better network performance, allowing more operations and nodes thanks to buffering before relaying
+- Daemon: Allow select on ini file how many connections can handle
+- Fixed a locking when deleting connections
+
+### Build 1.5.1.0 - 2017-02-20
+
+- Memory leak fixed on RPC-JSON commands
+- Memory leak fixed on node connections
+- Improved network speed processing new blocks/operations
+- Some minor bugs
+
+### Build 1.5.0.0 - 2017-02-15
+
+- Net protocol upgrade to 4-5
+- Introducing "more work" with high priority than "more high". Work is calculated based on target. Higher target (more work) is more important than higher length
+- Solved locking/crash bug on high connections (caused by bad thread locking)
+- Improved network connection
+- Added JSON-RPC port 4003 protection Whitelist (only allowed IP's can use JSON-RPC)
+
+
+### Build 1.4.3.0 - 2017-02-02
+
+- Adding "maturation" param to "JSON Operation object", return null when operation is not included on a blockchain yet, 0 means that is included in highest block and so on...
+- Fixing miner timestamp value to prevent invalid time
+
+### Build 1.4.2.0 - 2017-01-23
+
+- Max JSON-RPC miner connections is now 1000 (before, 10)
+- JSON-RPC miner enabled at pascalcoin_daemon (linux daemon)
+- Screen messages for daemon
+- pascalcoin_daemon.ini file for daemon
+
+### Build 1.4.1.0 - 2017-01-18
+
+- Improved JSON communications with Miner client (Port 4009 by default)
+- Deleted adding numeration to JSON miner clients (only sends miner name)
+- Minor changes
+
+### Build 1.4.0.0 - 2016-12-30
+
+- JSON-RPC changes:
+  - Added method "signsendto" to allow a off-line wallet sign transaction operations without being syncrhonized
+  - Added method "signchangekey" to allow a off-line wallet sign change key operations without being syncrhonized
+  - Added method "executeoperations" to allow a on-line wallet execute operations signed off-line
+  - Added method "operationsinfo" that will decode operations signed off-line
+  - Added param "max" at JSON-RPC method "getblocks"
+  - Changed param name "deep" for "depht" in "getaccountoperations". Deep will be available for compatibility.
+  - Changed result for "changekeys". Now returns a "JSON operation object" array with each change key operation result
+  - Changes on "JSON Operation object": May return a "valid" param and "errors" param
+- Corrected a memory leak when processing JSON-RPC calls
+- Better performance in connection protocol
+- Updated protocol available to 1
+- Updated net protocol to 3-4
+- Important bug corrected
+
+### Build 1.3.0.0 - 2016-11-24
+
+- JSON-RPC modifications:
+  - New param "b58_pubkey", can be used instead of "enc_pubkey": b58_pubkey is a Base58 encoded public key with checksum, is the value that Wallet exports/imports public key
+  - New JSON object type Public Key: "name","can_use","enc_pubkey","b58_pubkey","ec_nid","x" and "y" for each public key
+  - Added params "start" and "max" to "getaccountoperations". By default deep=100, max=100 and start=0, so will return last 100 operations made to an account
+  - Added params "start" and "max" to "getblockoperations". By default max=100 and start=0, so will return last 100 operations made to a block
+  - Added params "start" and "max" to "getwalletaccounts". By default max=100 and start=0, so will return first 100 accounts of the wallet
+  - Added params "start" and "max" to "getwalletpubkeys". By default max=100 and start=0, so will return first 100 public keys of the wallet
+    - Will return a Public key JSON object
+  - Method "decodepubkey" allows params "enc_pubkey" or "b58_pubkey" (if used together, returns error if not match)
+    - Will return a Public key JSON object
+  - Method "changekey" allows params "new_enc_pubkey" or "new_b58_pubkey" (if used together, returns error if not match)
+  - Method "getwalletaccounts" allows params "enc_pubkey" or "b58_pubkey" (if used together, returns error if not match)
+  - Method "getwalletaccountscount" allows params "enc_pubkey" or "b58_pubkey" (if used together, returns error if not match)
+  - Method "getwalletcoins" allows params "enc_pubkey" or "b58_pubkey" (if used together, returns error if not match)  
+  - Method "payloadencrypt"  allows params "enc_pubkey" or "b58_pubkey" when payload_method="pubkey" (if used together, returns error if not match)  
+  - Method "addnewkey" changed. Does not return an HEXASTRING with enc_pubkey, now returns a public key JSON object
+  - New methods:
+    - Method "changekeys". Similar to "changekey" but for multiple accounts at param "accounts" as a coma separated string (ex: "accounts"="1248,1753,85056"). Returns a JSON object with result information
+    - Method "lock" to lock wallet. Returns true if locked, returns false if wallet has no password (an empty string, must put a new password prior to lock)
+    - New method "getwalletpubkey". Search for "enc_pubkey" or "b58_pubkey" and returns a Public key JSON object
+- Corrected a issue saving last 5 .bank files
+- Improved protections for .bank corruption files
+- Added "open data folder" button on options form
+- Other minor changes
+
+### Build 1.2.0.0 - 2016-11-16
+
+- Account checksum values modified to be more easy and more distributed: Checksum = ((N * 101) MOD 89)+10
+- Allow find operations by "ophash"
+- Show Operation "ophash" in operation payload decoder
+- Added param "enc_pubkey" to "getwalletaccounts" JSON-RPC method to return only accounts from this public key
+- Added params "pow" and "sbh" to "nodestatus" JSON-RPC method
+- Added method "getwalletaccountscount" returning accounts count of the entire wallet or for a single "enc_pubkey"
+- Added method "getwalletcoins" returning coins of the entire wallet or for a signle "enc_pubkey"
+- Modified seed nodes distribution to send only checked IP nodes
+- Corrected invalid operation block index when showing account operations
+
+
+### Build 1.1.0.0 - 2016-11-03
+
+- JSON-RPC Server included
+- Minor changes
+
+
+### Build 1.0.9.0 - 2016-10-21
+
+- Corrected a BUG (BUG-101) that causes blocking connections when received more than 100 connections, causing "alone in the world" after a cert period time.
+- It's necessary to update because new version will refuse old versions to make network stable.
+
+
+### Build 1.0.8.0 - 2016-10-20
+
+- Cross compatible
+- Can compile with Delphi or Lazarus (Free Pascal)
+- New storage system. No more access database
+- Network hashrate calculation
+
+
+### Build 1.0.7.0 - 2016-10-10
+
+- Introducing basic JSON-RPC to allow GPU miners development (Third party).
+- See file "HOWTO_DEVELOP_GPU_MINER_FOR_PASCALCOIN.txt"
+- No more CPU mining due exists GPU mining
+
+
+### Build 1.0.6.0 - 2016-10-04
+
+- Memory leaks corrections
+- Introducing net protocol 2-3
+- Source code modified, next build will be compiled with Lazarus and FPC
+
+
+### Build 1.0.5.0 - 2016-09-21
+
+- Massive operations, selecting multiple accounts
+- Filter accounts by balance
+- Correct operations explorer order of operations for each block (descending order)
+- Minor changes
+
+
+### Build 1.0.4.0 - 2016-09-16
+
+- IMPORTANT: Introducing net protocol changes: Must update!
+- More and more and more stable
+- Prevents "Alone in the world" if everybody is updated ;-)
+- Invalid local time detector with corrections
+- IP nodes configurator
+
+
+### Build 1.0.3.0 - 2016-09-08
+
+- Important changes to database 
+- Peer cache
+- Issues with Connections
+- More stable
+- Miner key selector
+- Invalid local time detector
+
+
+### Build 1.0.2.0 - 2016-08-31
+
+- Improved hashing speed
+- Allow mining without opening external ports
+- Choose how many CPU's want to mine
+- Show real-time pending operations waiting to be included in the block
+- More stable
+- Some miner modifications
+
+### Build 1.0.1.0 - 2016-08-12
+
+- Included an option to Import/Export Wallet keys file
+- Some miner modifications
+
+
+### Build 1.0.0.0 - 2016-08-11
+
+- First stable version.
+- Created with Genesis block hardcoded
+- Published at same time than Genesis block. NO PREMINE