release-notes-0.13.1.md
1 Bitcoin Core version 0.13.1 is now available from: 2 3 <https://bitcoin.org/bin/bitcoin-core-0.13.1/> 4 5 This is a new minor version release, including activation parameters for the 6 segwit softfork, various bugfixes and performance improvements, as well as 7 updated translations. 8 9 Please report bugs using the issue tracker at github: 10 11 <https://github.com/bitcoin/bitcoin/issues> 12 13 To receive security and update notifications, please subscribe to: 14 15 <https://bitcoincore.org/en/list/announcements/join/> 16 17 Compatibility 18 ============== 19 20 Microsoft ended support for Windows XP on [April 8th, 2014](https://www.microsoft.com/en-us/WindowsForBusiness/end-of-xp-support), 21 an OS initially released in 2001. This means that not even critical security 22 updates will be released anymore. Without security updates, using a bitcoin 23 wallet on a XP machine is irresponsible at least. 24 25 In addition to that, with 0.12.x there have been varied reports of Bitcoin Core 26 randomly crashing on Windows XP. It is [not clear](https://github.com/bitcoin/bitcoin/issues/7681#issuecomment-217439891) 27 what the source of these crashes is, but it is likely that upstream 28 libraries such as Qt are no longer being tested on XP. 29 30 We do not have time nor resources to provide support for an OS that is 31 end-of-life. From 0.13.0 on, Windows XP is no longer supported. Users are 32 suggested to upgrade to a newer version of Windows, or install an alternative OS 33 that is supported. 34 35 No attempt is made to prevent installing or running the software on Windows XP, 36 you can still do so at your own risk, but do not expect it to work: do not 37 report issues about Windows XP to the issue tracker. 38 39 From 0.13.1 onwards OS X 10.7 is no longer supported. 0.13.0 was intended to work on 10.7+, 40 but severe issues with the libc++ version on 10.7.x keep it from running reliably. 41 0.13.1 now requires 10.8+, and will communicate that to 10.7 users, rather than crashing unexpectedly. 42 43 Notable changes 44 =============== 45 46 Segregated witness soft fork 47 ---------------------------- 48 49 Segregated witness (segwit) is a soft fork that, if activated, will 50 allow transaction-producing software to separate (segregate) transaction 51 signatures (witnesses) from the part of the data in a transaction that is 52 covered by the txid. This provides several immediate benefits: 53 54 - **Elimination of unwanted transaction malleability:** Segregating the witness 55 allows both existing and upgraded software to calculate the transaction 56 identifier (txid) of transactions without referencing the witness, which can 57 sometimes be changed by third-parties (such as miners) or by co-signers in a 58 multisig spend. This solves all known cases of unwanted transaction 59 malleability, which is a problem that makes programming Bitcoin wallet 60 software more difficult and which seriously complicates the design of smart 61 contracts for Bitcoin. 62 63 - **Capacity increase:** Segwit transactions contain new fields that are not 64 part of the data currently used to calculate the size of a block, which 65 allows a block containing segwit transactions to hold more data than allowed 66 by the current maximum block size. Estimates based on the transactions 67 currently found in blocks indicate that if all wallets switch to using 68 segwit, the network will be able to support about 70% more transactions. The 69 network will also be able to support more of the advanced-style payments 70 (such as multisig) than it can support now because of the different weighting 71 given to different parts of a transaction after segwit activates (see the 72 following section for details). 73 74 - **Weighting data based on how it affects node performance:** Some parts of 75 each Bitcoin block need to be stored by nodes in order to validate future 76 blocks; other parts of a block can be immediately forgotten (pruned) or used 77 only for helping other nodes sync their copy of the block chain. One large 78 part of the immediately prunable data are transaction signatures (witnesses), 79 and segwit makes it possible to give a different "weight" to segregated 80 witnesses to correspond with the lower demands they place on node resources. 81 Specifically, each byte of a segregated witness is given a weight of 1, each 82 other byte in a block is given a weight of 4, and the maximum allowed weight 83 of a block is 4 million. Weighting the data this way better aligns the most 84 profitable strategy for creating blocks with the long-term costs of block 85 validation. 86 87 - **Signature covers value:** A simple improvement in the way signatures are 88 generated in segwit simplifies the design of secure signature generators 89 (such as hardware wallets), reduces the amount of data the signature 90 generator needs to download, and allows the signature generator to operate 91 more quickly. This is made possible by having the generator sign the amount 92 of bitcoins they think they are spending, and by having full nodes refuse to 93 accept those signatures unless the amount of bitcoins being spent is exactly 94 the same as was signed. For non-segwit transactions, wallets instead had to 95 download the complete previous transactions being spent for every payment 96 they made, which could be a slow operation on hardware wallets and in other 97 situations where bandwidth or computation speed was constrained. 98 99 - **Linear scaling of sighash operations:** In 2015 a block was produced that 100 required about 25 seconds to validate on modern hardware because of the way 101 transaction signature hashes are performed. Other similar blocks, or blocks 102 that could take even longer to validate, can still be produced today. The 103 problem that caused this can't be fixed in a soft fork without unwanted 104 side-effects, but transactions that opt-in to using segwit will now use a 105 different signature method that doesn't suffer from this problem and doesn't 106 have any unwanted side-effects. 107 108 - **Increased security for multisig:** Bitcoin addresses (both P2PKH addresses 109 that start with a '1' and P2SH addresses that start with a '3') use a hash 110 function known as RIPEMD-160. For P2PKH addresses, this provides about 160 111 bits of security---which is beyond what cryptographers believe can be broken 112 today. But because P2SH is more flexible, only about 80 bits of security is 113 provided per address. Although 80 bits is very strong security, it is within 114 the realm of possibility that it can be broken by a powerful adversary. 115 Segwit allows advanced transactions to use the SHA256 hash function instead, 116 which provides about 128 bits of security (that is 281 trillion times as 117 much security as 80 bits and is equivalent to the maximum bits of security 118 believed to be provided by Bitcoin's choice of parameters for its Elliptic 119 Curve Digital Security Algorithm [ECDSA].) 120 121 - **More efficient almost-full-node security** Satoshi Nakamoto's original 122 Bitcoin paper describes a method for allowing newly-started full nodes to 123 skip downloading and validating some data from historic blocks that are 124 protected by large amounts of proof of work. Unfortunately, Nakamoto's 125 method can't guarantee that a newly-started node using this method will 126 produce an accurate copy of Bitcoin's current ledger (called the UTXO set), 127 making the node vulnerable to falling out of consensus with other nodes. 128 Although the problems with Nakamoto's method can't be fixed in a soft fork, 129 Segwit accomplishes something similar to his original proposal: it makes it 130 possible for a node to optionally skip downloading some blockchain data 131 (specifically, the segregated witnesses) while still ensuring that the node 132 can build an accurate copy of the UTXO set for the block chain with the most 133 proof of work. Segwit enables this capability at the consensus layer, but 134 note that Bitcoin Core does not provide an option to use this capability as 135 of this 0.13.1 release. 136 137 - **Script versioning:** Segwit makes it easy for future soft forks to allow 138 Bitcoin users to individually opt-in to almost any change in the Bitcoin 139 Script language when those users receive new transactions. Features 140 currently being researched by Bitcoin Core contributors that may use this 141 capability include support for Schnorr signatures, which can improve the 142 privacy and efficiency of multisig transactions (or transactions with 143 multiple inputs), and Merklized Abstract Syntax Trees (MAST), which can 144 improve the privacy and efficiency of scripts with two or more conditions. 145 Other Bitcoin community members are studying several other improvements 146 that can be made using script versioning. 147 148 Activation for the segwit soft fork is being managed using BIP9 149 versionbits. Segwit's version bit is bit 1, and nodes will begin 150 tracking which blocks signal support for segwit at the beginning of the 151 first retarget period after segwit's start date of 15 November 2016. If 152 95% of blocks within a 2,016-block retarget period (about two weeks) 153 signal support for segwit, the soft fork will be locked in. After 154 another 2,016 blocks, segwit will activate. 155 156 For more information about segwit, please see the [segwit FAQ][], the 157 [segwit wallet developers guide][] or BIPs [141][BIP141], [143][BIP143], 158 [144][BIP144], and [145][BIP145]. If you're a miner or mining pool 159 operator, please see the [versionbits FAQ][] for information about 160 signaling support for a soft fork. 161 162 [Segwit FAQ]: https://bitcoincore.org/en/2016/01/26/segwit-benefits/ 163 [segwit wallet developers guide]: https://bitcoincore.org/en/segwit_wallet_dev/ 164 [BIP141]: https://github.com/bitcoin/bips/blob/master/bip-0141.mediawiki 165 [BIP143]: https://github.com/bitcoin/bips/blob/master/bip-0143.mediawiki 166 [BIP144]: https://github.com/bitcoin/bips/blob/master/bip-0144.mediawiki 167 [BIP145]: https://github.com/bitcoin/bips/blob/master/bip-0145.mediawiki 168 [versionbits FAQ]: https://bitcoincore.org/en/2016/06/08/version-bits-miners-faq/ 169 170 171 Null dummy soft fork 172 ------------------- 173 174 Combined with the segwit soft fork is an additional change that turns a 175 long-existing network relay policy into a consensus rule. The 176 `OP_CHECKMULTISIG` and `OP_CHECKMULTISIGVERIFY` opcodes consume an extra 177 stack element ("dummy element") after signature validation. The dummy 178 element is not inspected in any manner, and could be replaced by any 179 value without invalidating the script. 180 181 Because any value can be used for this dummy element, it's possible for 182 a third-party to insert data into other people's transactions, changing 183 the transaction's txid (called transaction malleability) and possibly 184 causing other problems. 185 186 Since Bitcoin Core 0.10.0, nodes have defaulted to only relaying and 187 mining transactions whose dummy element was a null value (0x00, also 188 called OP_0). The null dummy soft fork turns this relay rule into a 189 consensus rule both for non-segwit transactions and segwit transactions, 190 so that this method of mutating transactions is permanently eliminated 191 from the network. 192 193 Signaling for the null dummy soft fork is done by signaling support 194 for segwit, and the null dummy soft fork will activate at the same time 195 as segwit. 196 197 For more information, please see [BIP147][]. 198 199 [BIP147]: https://github.com/bitcoin/bips/blob/master/bip-0147.mediawiki 200 201 Low-level RPC changes 202 --------------------- 203 204 - `importprunedfunds` only accepts two required arguments. Some versions accept 205 an optional third arg, which was always ignored. Make sure to never pass more 206 than two arguments. 207 208 209 Linux ARM builds 210 ---------------- 211 212 With the 0.13.0 release, pre-built Linux ARM binaries were added to the set of 213 uploaded executables. Additional detail on the ARM architecture targeted by each 214 is provided below. 215 216 The following extra files can be found in the download directory or torrent: 217 218 - `bitcoin-${VERSION}-arm-linux-gnueabihf.tar.gz`: Linux binaries targeting 219 the 32-bit ARMv7-A architecture. 220 - `bitcoin-${VERSION}-aarch64-linux-gnu.tar.gz`: Linux binaries targeting 221 the 64-bit ARMv8-A architecture. 222 223 ARM builds are still experimental. If you have problems on a certain device or 224 Linux distribution combination please report them on the bug tracker, it may be 225 possible to resolve them. Note that the device you use must be (backward) 226 compatible with the architecture targeted by the binary that you use. 227 For example, a Raspberry Pi 2 Model B or Raspberry Pi 3 Model B (in its 32-bit 228 execution state) device, can run the 32-bit ARMv7-A targeted binary. However, 229 no model of Raspberry Pi 1 device can run either binary because they are all 230 ARMv6 architecture devices that are not compatible with ARMv7-A or ARMv8-A. 231 232 Note that Android is not considered ARM Linux in this context. The executables 233 are not expected to work out of the box on Android. 234 235 236 0.13.1 Change log 237 ================= 238 239 Detailed release notes follow. This overview includes changes that affect 240 behavior, not code moves, refactors and string updates. For convenience in locating 241 the code changes and accompanying discussion, both the pull request and 242 git merge commit are mentioned. 243 244 ### Consensus 245 - #8636 `9dfa0c8` Implement NULLDUMMY softfork (BIP147) (jl2012) 246 - #8848 `7a34a46` Add NULLDUMMY verify flag in bitcoinconsensus.h (jl2012) 247 - #8937 `8b66659` Define start and end time for segwit deployment (sipa) 248 249 ### RPC and other APIs 250 - #8581 `526d2b0` Drop misleading option in importprunedfunds (MarcoFalke) 251 - #8699 `a5ec248` Remove createwitnessaddress RPC command (jl2012) 252 - #8780 `794b007` Deprecate getinfo (MarcoFalke) 253 - #8832 `83ad563` Throw JSONRPCError when utxo set can not be read (MarcoFalke) 254 - #8884 `b987348` getblockchaininfo help: pruneheight is the lowest, not highest, block (luke-jr) 255 - #8858 `3f508ed` rpc: Generate auth cookie in hex instead of base64 (laanwj) 256 - #8951 `7c2bf4b` RPC/Mining: getblocktemplate: Update and fix formatting of help (luke-jr) 257 258 ### Block and transaction handling 259 - #8611 `a9429ca` Reduce default number of blocks to check at startup (sipa) 260 - #8634 `3e80ab7` Add policy: null signature for failed CHECK(MULTI)SIG (jl2012) 261 - #8525 `1672225` Do not store witness txn in rejection cache (sipa) 262 - #8499 `9777fe1` Add several policy limits and disable uncompressed keys for segwit scripts (jl2012) 263 - #8526 `0027672` Make non-minimal OP_IF/NOTIF argument non-standard for P2WSH (jl2012) 264 - #8524 `b8c79a0` Precompute sighashes (sipa) 265 - #8651 `b8c79a0` Predeclare PrecomputedTransactionData as struct (sipa) 266 267 ### P2P protocol and network code 268 - #8740 `42ea51a` No longer send local address in addrMe (laanwj) 269 - #8427 `69d1cd2` Ignore `notfound` P2P messages (laanwj) 270 - #8573 `4f84082` Set jonasschnellis dns-seeder filter flag (jonasschnelli) 271 - #8712 `23feab1` Remove maxuploadtargets recommended minimum (jonasschnelli) 272 - #8862 `7ae6242` Fix a few cases where messages were sent after requested disconnect (theuni) 273 - #8393 `fe1975a` Support for compact blocks together with segwit (sipa) 274 - #8282 `2611ad7` Feeler connections to increase online addrs in the tried table (EthanHeilman) 275 - #8612 `2215c22` Check for compatibility with download in FindNextBlocksToDownload (sipa) 276 - #8606 `bbf379b` Fix some locks (sipa) 277 - #8594 `ab295bb` Do not add random inbound peers to addrman (gmaxwell) 278 - #8940 `5b4192b` Add x9 service bit support to dnsseed.bluematt.me, seed.bitcoinstats.com (TheBlueMatt, cdecker) 279 - #8944 `685e4c7` Remove bogus assert on number of oubound connections. (TheBlueMatt) 280 - #8949 `0dbc48a` Be more agressive in getting connections to peers with relevant services (gmaxwell) 281 282 ### Build system 283 - #8293 `fa5b249` Allow building libbitcoinconsensus without any univalue (luke-jr) 284 - #8492 `8b0bdd3` Allow building bench_bitcoin by itself (luke-jr) 285 - #8563 `147003c` Add configure check for -latomic (ajtowns) 286 - #8626 `ea51b0f` Berkeley DB v6 compatibility fix (netsafe) 287 - #8520 `75f2065` Remove check for `openssl/ec.h` (laanwj) 288 289 ### GUI 290 - #8481 `d9f0d4e` Fix minimize and close bugs (adlawren) 291 - #8487 `a37cec5` Persist the datadir after option reset (achow101) 292 - #8697 `41fd852` Fix op order to append first alert (rodasmith) 293 - #8678 `8e03382` Fix UI bug that could result in paying unexpected fee (jonasschnelli) 294 - #8911 `7634d8e` Translate all files, even if wallet disabled (laanwj) 295 - #8540 `1db3352` Fix random segfault when closing "Choose data directory" dialog (laanwj) 296 - #7579 `f1c0d78` Show network/chain errors in the GUI (jonasschnelli) 297 298 ### Wallet 299 - #8443 `464dedd` Trivial cleanup of HD wallet changes (jonasschnelli) 300 - #8539 `cb07f19` CDB: fix debug output (crowning-) 301 - #8664 `091cdeb` Fix segwit-related wallet bug (sdaftuar) 302 - #8693 `c6a6291` Add witness address to address book (instagibbs) 303 - #8765 `6288659` Remove "unused" ThreadFlushWalletDB from removeprunedfunds (jonasschnelli) 304 305 ### Tests and QA 306 - #8713 `ae8c7df` create_cache: Delete temp dir when done (MarcoFalke) 307 - #8716 `e34374e` Check legacy wallet as well (MarcoFalke) 308 - #8750 `d6ebe13` Refactor RPCTestHandler to prevent TimeoutExpired (MarcoFalke) 309 - #8652 `63462c2` remove root test directory for RPC tests (yurizhykin) 310 - #8724 `da94272` walletbackup: Sync blocks inside the loop (MarcoFalke) 311 - #8400 `bea02dc` enable rpcbind_test (yurizhykin) 312 - #8417 `f70be14` Add walletdump RPC test (including HD- & encryption-tests) (jonasschnelli) 313 - #8419 `a7aa3cc` Enable size accounting in mining unit tests (sdaftuar) 314 - #8442 `8bb1efd` Rework hd wallet dump test (MarcoFalke) 315 - #8528 `3606b6b` Update p2p-segwit.py to reflect correct behavior (instagibbs) 316 - #8531 `a27cdd8` abandonconflict: Use assert_equal (MarcoFalke) 317 - #8667 `6b07362` Fix SIGHASH_SINGLE bug in test_framework SignatureHash (jl2012) 318 - #8673 `03b0196` Fix obvious assignment/equality error in test (JeremyRubin) 319 - #8739 `cef633c` Fix broken sendcmpct test in p2p-compactblocks.py (sdaftuar) 320 - #8418 `ff893aa` Add tests for compact blocks (sdaftuar) 321 - #8803 `375437c` Ping regularly in p2p-segwit.py to keep connection alive (jl2012) 322 - #8827 `9bbe66e` Split up slow RPC calls to avoid pruning test timeouts (sdaftuar) 323 - #8829 `2a8bca4` Add bitcoin-tx JSON tests (jnewbery) 324 - #8834 `1dd1783` blockstore: Switch to dumb dbm (MarcoFalke) 325 - #8835 `d87227d` nulldummy.py: Don't run unused code (MarcoFalke) 326 - #8836 `eb18cc1` bitcoin-util-test.py should fail if the output file is empty (jnewbery) 327 - #8839 `31ab2f8` Avoid ConnectionResetErrors during RPC tests (laanwj) 328 - #8840 `cbc3fe5` Explicitly set encoding to utf8 when opening text files (laanwj) 329 - #8841 `3e4abb5` Fix nulldummy test (jl2012) 330 - #8854 `624a007` Fix race condition in p2p-compactblocks test (sdaftuar) 331 - #8857 `1f60d45` mininode: Only allow named args in wait_until (MarcoFalke) 332 - #8860 `0bee740` util: Move wait_bitcoinds() into stop_nodes() (MarcoFalke) 333 - #8882 `b73f065` Fix race conditions in p2p-compactblocks.py and sendheaders.py (sdaftuar) 334 - #8904 `cc6f551` Fix compact block shortids for a test case (dagurval) 335 336 ### Documentation 337 - #8754 `0e2c6bd` Target protobuf 2.6 in OS X build notes. (fanquake) 338 - #8461 `b17a3f9` Document return value of networkhashps for getmininginfo RPC endpoint (jlopp) 339 - #8512 `156e305` Corrected JSON typo on setban of net.cpp (sevastos) 340 - #8683 `8a7d7ff` Fix incorrect file name bitcoin.qrc (bitcoinsSG) 341 - #8891 `5e0dd9e` Update bips.md for Segregated Witness (fanquake) 342 - #8545 `863ae74` Update git-subtree-check.sh README (MarcoFalke) 343 - #8607 `486650a` Fix doxygen off-by-one comments, fix typos (MarcoFalke) 344 - #8560 `c493f43` Fix two VarInt examples in serialize.h (cbarcenas) 345 - #8737 `084cae9` UndoReadFromDisk works on undo files (rev), not on block files (paveljanik) 346 - #8625 `0a35573` Clarify statement about parallel jobs in rpc-tests.py (isle2983) 347 - #8624 `0e6d753` build: Mention curl (MarcoFalke) 348 - #8604 `b09e13c` build,doc: Update for 0.13.0+ and OpenBSD 5.9 (laanwj) 349 - #8939 `06d15fb` Update implemented bips for 0.13.1 (sipa) 350 351 ### Miscellaneous 352 - #8742 `d31ac72` Specify Protobuf version 2 in paymentrequest.proto (fanquake) 353 - #8414,#8558,#8676,#8700,#8701,#8702 Add missing copyright headers (isle2983, kazcw) 354 - #8899 `4ed2627` Fix wake from sleep issue with Boost 1.59.0 (fanquake) 355 - #8817 `bcf3806` update bitcoin-tx to output witness data (jnewbery) 356 - #8513 `4e5fc31` Fix a type error that would not compile on OSX. (JeremyRubin) 357 - #8392 `30eac2d` Fix several node initialization issues (sipa) 358 - #8548 `305d8ac` Use `__func__` to get function name for output printing (MarcoFalke) 359 - #8291 `a987431` [util] CopyrightHolders: Check for untranslated substitution (MarcoFalke) 360 361 Credits 362 ======= 363 364 Thanks to everyone who directly contributed to this release: 365 366 - adlawren 367 - Alexey Vesnin 368 - Anders Øyvind Urke-Sætre 369 - Andrew Chow 370 - Anthony Towns 371 - BtcDrak 372 - Chris Stewart 373 - Christian Barcenas 374 - Christian Decker 375 - Cory Fields 376 - crowning- 377 - Dagur Valberg Johannsson 378 - David A. Harding 379 - Eric Lombrozo 380 - Ethan Heilman 381 - fanquake 382 - Gaurav Rana 383 - Gregory Maxwell 384 - instagibbs 385 - isle2983 386 - Jameson Lopp 387 - Jeremy Rubin 388 - jnewbery 389 - Johnson Lau 390 - Jonas Schnelli 391 - jonnynewbs 392 - Justin Camarena 393 - Kaz Wesley 394 - leijurv 395 - Luke Dashjr 396 - MarcoFalke 397 - Marty Jones 398 - Matt Corallo 399 - Micha 400 - Michael Ford 401 - mruddy 402 - Pavel Janík 403 - Pieter Wuille 404 - rodasmith 405 - Sev 406 - Suhas Daftuar 407 - whythat 408 - Wladimir J. van der Laan 409 410 As well as everyone that helped translating on [Transifex](https://www.transifex.com/projects/p/bitcoin/).