Technical background of version 1 Bitcoin addresses - Revision history

Yojoots: Update Base58Check address formatting details

2021-02-25T06:45:13Z

Update Base58Check address formatting details

← Older revision		Revision as of 06:45, 25 February 2021
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	Bitcoin addresses contain a built-in check code, so it's generally not possible to send Bitcoins to a mistyped address. However, if the address is well-formed but no one owns it (or the owner lost their wallet.dat), any coins sent to that address will be lost forever.		Bitcoin addresses contain a built-in check code, so it's generally not possible to send Bitcoins to a mistyped address. However, if the address is well-formed but no one owns it (or the owner lost their wallet.dat), any coins sent to that address will be lost forever.

	Hash values and the checksum data are converted to an alpha-numeric representation using a custom scheme: the [[Base58Check encoding]] scheme. Under Base58Check, addresses can contain all alphanumeric characters except 0, O, I, and l. ~~Normal~~ addresses ~~currently always~~ start with 1 (addresses ~~from script hashes~~ use 3)~~, though this might change in a future version~~. Testnet addresses usually start with ''m'' or ''n''. ~~Mainline~~ addresses can be 25-34 characters in length, and testnet addresses can be 26-34 characters in length. Most addresses are 33 or 34 characters long.		Hash values and the checksum data are converted to an alpha-numeric representation using a custom scheme: the [[Base58Check encoding]] scheme. Under Base58Check, addresses can contain all alphanumeric characters except 0, O, I, and l. Mainnet [[P2PKH]] addresses start with <code>1</code>, while [[P2SH]] addresses start with <code>3</code> ([[Bech32]] addresses start with <code>bc1</code> and do not use Base58Check encoding). Testnet addresses usually start with <code>m</code> or <code>n</code>. Mainnet addresses can be 25-34 characters in length, and testnet addresses can be 26-34 characters in length. Most addresses are 33 or 34 characters long.

	== Collisions (lack thereof) ==		== Collisions (lack thereof) ==

Gmaxwell: /* How to create Bitcoin Address */ no one should be using this to actually generate addresses.

2019-03-28T08:33:55Z

How to create Bitcoin Address: no one should be using this to actually generate addresses.

← Older revision		Revision as of 08:33, 28 March 2019
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	==How to create Bitcoin Address==		==How to create Bitcoin Address==

			The correct way to create a Bitcoin address is to use well tested, open source, peer reviewed wallet software. Manually handling keys has resulted in funds loss over and over again. Unlike other centralized systems losses in Bitcoin are usually unrecoverable.

			Here is a brief overview of how address generation works, for informational purposes:

	0 - Having a private [[ECDSA]] key		0 - Having a private [[ECDSA]] key
	18e14a7b6a307f426a94f8114701e7c8e774e7f9a47e2c2035db29a206321725		18e14a7b6a307f426a94f8114701e7c8e774e7f9a47e2c2035db29a206321725

Gmaxwell: /* Collisions (lack thereof) */ LBC is malware (remote code execution) and also largely irrelevant for section. The text was confusing second preimages and collisions too.

2019-03-28T08:30:10Z

Collisions (lack thereof): LBC is malware (remote code execution) and also largely irrelevant for section. The text was confusing second preimages and collisions too.

← Older revision		Revision as of 08:30, 28 March 2019
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	== Collisions (lack thereof) ==		== Collisions (lack thereof) ==
	Since Bitcoin addresses are basically random numbers, it is possible, although extremely unlikely, for two people to independently generate the same address. This is called a [[Wikipedia:Collision_(computer_science)\|collision]]. If this happens, then both the original owner of the address and the colliding owner could spend money sent to that address. It would not be possible for the colliding person to spend the original owner's entire wallet (or vice versa). If you were to intentionally try to make a collision, it would currently take 2^107 times longer to generate a colliding Bitcoin address than to generate a block. As long as the signing and hashing algorithms remain cryptographically strong, it will likely always be more profitable to collect generations and [[transaction fee\|transaction fees]] than to try to create collisions, as demonstrated by projects like the [https://lbc.cryptoguru.org/ Large Bitcoin Collider] which attempt to generate address collisions.		Since Bitcoin addresses are basically random numbers, it is possible, although extremely unlikely, for two people to independently generate the same address. This is called a [[Wikipedia:Collision_(computer_science)\|collision]]. If this happens, then both the original owner of the address and the colliding owner could spend money sent to that address. It would not be possible for the colliding person to spend the original owner's entire wallet (or vice versa).

	It is more likely that the Earth is destroyed in the next 5 seconds, than that a collision occur in the next millenium.		But because the space of possible addresses is so astronomically large it is more likely that the Earth is destroyed in the next 5 seconds, than that a collision occur in the next millenium.

	==How to create Bitcoin Address==		==How to create Bitcoin Address==

Jbaczuk: /* How to create Bitcoin Address */ Finished adding examples

2018-06-06T05:36:03Z

How to create Bitcoin Address: Finished adding examples

← Older revision		Revision as of 05:36, 6 June 2018
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	==How to create Bitcoin Address==		==How to create Bitcoin Address==
	0 - Having a private [[ECDSA]] key		0 - Having a private [[ECDSA]] key
	~~18E14A7B6A307F426A94F8114701E7C8E774E7F9A47E2C2035DB29A206321725~~		18e14a7b6a307f426a94f8114701e7c8e774e7f9a47e2c2035db29a206321725
	1 - Take the corresponding public key generated with it (33 bytes, 1 byte ~~0x03~~, and 32 bytes corresponding to X coordinate)		1 - Take the corresponding public key generated with it (33 bytes, 1 byte 0x02 (y-coord is even), and 32 bytes corresponding to X coordinate)
	~~0350863AD64A87AE8A2FE83C1AF1A8403CB53F53E486D8511DAD8A04887E5B2352~~		0250863ad64a87ae8a2fe83c1af1a8403cb53f53e486d8511dad8a04887e5b2352
	2 - Perform [[SHA-256]] hashing on the public key		2 - Perform [[SHA-256]] hashing on the public key
	~~FIXME: Put an example here~~		0b7c28c9b7290c98d7438e70b3d3f7c848fbd7d1dc194ff83f4f7cc9b1378e98
	3 - Perform [[RIPEMD-160]] hashing on the result of SHA-256		3 - Perform [[RIPEMD-160]] hashing on the result of SHA-256
	~~FIXME: Put an example here~~		f54a5851e9372b87810a8e60cdd2e7cfd80b6e31
	4 - Add version byte in front of RIPEMD-160 hash (0x00 for Main Network)		4 - Add version byte in front of RIPEMD-160 hash (0x00 for Main Network)
	~~FIXME: Put an example here~~		00f54a5851e9372b87810a8e60cdd2e7cfd80b6e31
	''(note that below steps are the [[Base58Check encoding]], which has multiple library options available implementing it)''<br>		''(note that below steps are the [[Base58Check encoding]], which has multiple library options available implementing it)''<br>
	5 - Perform SHA-256 hash on the extended RIPEMD-160 result		5 - Perform SHA-256 hash on the extended RIPEMD-160 result
	~~FIXME: Put an example here~~		ad3c854da227c7e99c4abfad4ea41d71311160df2e415e713318c70d67c6b41c
	6 - Perform SHA-256 hash on the result of the previous SHA-256 hash		6 - Perform SHA-256 hash on the result of the previous SHA-256 hash
	~~FIXME: Put an example here~~		c7f18fe8fcbed6396741e58ad259b5cb16b7fd7f041904147ba1dcffabf747fd
	7 - Take the first 4 bytes of the second SHA-256 hash. This is the address checksum		7 - Take the first 4 bytes of the second SHA-256 hash. This is the address checksum
	~~FIXME: Put an example here~~		c7f18fe8
	8 - Add the 4 checksum bytes from stage 7 at the end of extended RIPEMD-160 hash from stage 4. This is the 25-byte binary Bitcoin Address.		8 - Add the 4 checksum bytes from stage 7 at the end of extended RIPEMD-160 hash from stage 4. This is the 25-byte binary Bitcoin Address.
	~~FIXME: Put an example here~~		00f54a5851e9372b87810a8e60cdd2e7cfd80b6e31c7f18fe8
	9 - Convert the result from a byte string into a base58 string using [[Base58Check encoding]]. This is the most commonly used Bitcoin Address format		9 - Convert the result from a byte string into a base58 string using [[Base58Check encoding]]. This is the most commonly used Bitcoin Address format
	~~FIXME: Put an example here~~		1PMycacnJaSqwwJqjawXBErnLsZ7RkXUAs

	==See Also==		==See Also==

Luke-jr: /* How to create Bitcoin Address */ Needs examples...

2018-04-19T08:02:36Z

How to create Bitcoin Address: Needs examples...

← Older revision		Revision as of 08:02, 19 April 2018
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	0350863AD64A87AE8A2FE83C1AF1A8403CB53F53E486D8511DAD8A04887E5B2352		0350863AD64A87AE8A2FE83C1AF1A8403CB53F53E486D8511DAD8A04887E5B2352
	2 - Perform [[SHA-256]] hashing on the public key		2 - Perform [[SHA-256]] hashing on the public key
			FIXME: Put an example here
	3 - Perform [[RIPEMD-160]] hashing on the result of SHA-256		3 - Perform [[RIPEMD-160]] hashing on the result of SHA-256
			FIXME: Put an example here
	4 - Add version byte in front of RIPEMD-160 hash (0x00 for Main Network)		4 - Add version byte in front of RIPEMD-160 hash (0x00 for Main Network)
			FIXME: Put an example here
	''(note that below steps are the [[Base58Check encoding]], which has multiple library options available implementing it)''<br>		''(note that below steps are the [[Base58Check encoding]], which has multiple library options available implementing it)''<br>
	5 - Perform SHA-256 hash on the extended RIPEMD-160 result		5 - Perform SHA-256 hash on the extended RIPEMD-160 result
			FIXME: Put an example here
	6 - Perform SHA-256 hash on the result of the previous SHA-256 hash		6 - Perform SHA-256 hash on the result of the previous SHA-256 hash
			FIXME: Put an example here
	7 - Take the first 4 bytes of the second SHA-256 hash. This is the address checksum		7 - Take the first 4 bytes of the second SHA-256 hash. This is the address checksum
			FIXME: Put an example here
	8 - Add the 4 checksum bytes from stage 7 at the end of extended RIPEMD-160 hash from stage 4. This is the 25-byte binary Bitcoin Address.		8 - Add the 4 checksum bytes from stage 7 at the end of extended RIPEMD-160 hash from stage 4. This is the 25-byte binary Bitcoin Address.
			FIXME: Put an example here
	9 - Convert the result from a byte string into a base58 string using [[Base58Check encoding]]. This is the most commonly used Bitcoin Address format		9 - Convert the result from a byte string into a base58 string using [[Base58Check encoding]]. This is the most commonly used Bitcoin Address format
			FIXME: Put an example here

	==See Also==		==See Also==

Luke-jr: /* How to create Bitcoin Address */ Change to compressed keys

2018-04-19T08:02:09Z

How to create Bitcoin Address: Change to compressed keys

← Older revision		Revision as of 08:02, 19 April 2018
Line 27:		Line 27:
	0 - Having a private [[ECDSA]] key		0 - Having a private [[ECDSA]] key
	18E14A7B6A307F426A94F8114701E7C8E774E7F9A47E2C2035DB29A206321725		18E14A7B6A307F426A94F8114701E7C8E774E7F9A47E2C2035DB29A206321725
	1 - Take the corresponding public key generated with it (65 bytes, 1 byte ~~0x04~~, 32 bytes corresponding to X ~~coordinate, 32 bytes corresponding to Y~~ coordinate)		1 - Take the corresponding public key generated with it (33 bytes, 1 byte 0x03, and 32 bytes corresponding to X coordinate)
	~~0450863AD64A87AE8A2FE83C1AF1A8403CB53F53E486D8511DAD8A04887E5B23522CD470243453A299FA9E77237716103ABC11A1DF38855ED6F2EE187E9C582BA6~~		0350863AD64A87AE8A2FE83C1AF1A8403CB53F53E486D8511DAD8A04887E5B2352
	2 - Perform [[SHA-256]] hashing on the public key		2 - Perform [[SHA-256]] hashing on the public key
	~~600FFE422B4E00731A59557A5CCA46CC183944191006324A447BDB2D98D4B408~~
	3 - Perform [[RIPEMD-160]] hashing on the result of SHA-256		3 - Perform [[RIPEMD-160]] hashing on the result of SHA-256
	~~010966776006953D5567439E5E39F86A0D273BEE~~
	4 - Add version byte in front of RIPEMD-160 hash (0x00 for Main Network)		4 - Add version byte in front of RIPEMD-160 hash (0x00 for Main Network)
	~~00010966776006953D5567439E5E39F86A0D273BEE~~
	''(note that below steps are the [[Base58Check encoding]], which has multiple library options available implementing it)''<br>		''(note that below steps are the [[Base58Check encoding]], which has multiple library options available implementing it)''<br>
	5 - Perform SHA-256 hash on the extended RIPEMD-160 result		5 - Perform SHA-256 hash on the extended RIPEMD-160 result
	~~445C7A8007A93D8733188288BB320A8FE2DEBD2AE1B47F0F50BC10BAE845C094~~
	6 - Perform SHA-256 hash on the result of the previous SHA-256 hash		6 - Perform SHA-256 hash on the result of the previous SHA-256 hash
	~~D61967F63C7DD183914A4AE452C9F6AD5D462CE3D277798075B107615C1A8A30~~
	7 - Take the first 4 bytes of the second SHA-256 hash. This is the address checksum		7 - Take the first 4 bytes of the second SHA-256 hash. This is the address checksum
	~~D61967F6~~
	8 - Add the 4 checksum bytes from stage 7 at the end of extended RIPEMD-160 hash from stage 4. This is the 25-byte binary Bitcoin Address.		8 - Add the 4 checksum bytes from stage 7 at the end of extended RIPEMD-160 hash from stage 4. This is the 25-byte binary Bitcoin Address.
	~~00010966776006953D5567439E5E39F86A0D273BEED61967F6~~
	9 - Convert the result from a byte string into a base58 string using [[Base58Check encoding]]. This is the most commonly used Bitcoin Address format		9 - Convert the result from a byte string into a base58 string using [[Base58Check encoding]]. This is the most commonly used Bitcoin Address format
	~~16UwLL9Risc3QfPqBUvKofHmBQ7wMtjvM~~

	==See Also==		==See Also==

Randolf: /* Collisions (lack thereof) */ Referred to the Large Bitcoin Collider project as an example

2017-10-28T06:34:49Z

Collisions (lack thereof): Referred to the Large Bitcoin Collider project as an example

← Older revision		Revision as of 06:34, 28 October 2017
Line 20:		Line 20:

	== Collisions (lack thereof) ==		== Collisions (lack thereof) ==
	Since Bitcoin addresses are basically random numbers, it is possible, although extremely unlikely, for two people to independently generate the same address. This is called a [[Wikipedia:Collision_(computer_science)\|collision]]. If this happens, then both the original owner of the address and the colliding owner could spend money sent to that address. It would not be possible for the colliding person to spend the original owner's entire wallet (or vice versa). If you were to intentionally try to make a collision, it would currently take 2^107 times longer to generate a colliding Bitcoin address than to generate a block. As long as the signing and hashing algorithms remain cryptographically strong, it will likely always be more profitable to collect generations and [[transaction fee\|transaction fees]] than to try to create collisions.		Since Bitcoin addresses are basically random numbers, it is possible, although extremely unlikely, for two people to independently generate the same address. This is called a [[Wikipedia:Collision_(computer_science)\|collision]]. If this happens, then both the original owner of the address and the colliding owner could spend money sent to that address. It would not be possible for the colliding person to spend the original owner's entire wallet (or vice versa). If you were to intentionally try to make a collision, it would currently take 2^107 times longer to generate a colliding Bitcoin address than to generate a block. As long as the signing and hashing algorithms remain cryptographically strong, it will likely always be more profitable to collect generations and [[transaction fee\|transaction fees]] than to try to create collisions, as demonstrated by projects like the [https://lbc.cryptoguru.org/ Large Bitcoin Collider] which attempt to generate address collisions.

	It is more likely that the Earth is destroyed in the next 5 seconds, than that a collision occur in the next millenium.		It is more likely that the Earth is destroyed in the next 5 seconds, than that a collision occur in the next millenium.

JonathanCross: /* How to create Bitcoin Address */ Linking first use of RIPEMD-160 and SHA-256.

2016-01-29T15:46:19Z

How to create Bitcoin Address: Linking first use of RIPEMD-160 and SHA-256.

← Older revision		Revision as of 15:46, 29 January 2016
Line 29:		Line 29:
	1 - Take the corresponding public key generated with it (65 bytes, 1 byte 0x04, 32 bytes corresponding to X coordinate, 32 bytes corresponding to Y coordinate)		1 - Take the corresponding public key generated with it (65 bytes, 1 byte 0x04, 32 bytes corresponding to X coordinate, 32 bytes corresponding to Y coordinate)
	0450863AD64A87AE8A2FE83C1AF1A8403CB53F53E486D8511DAD8A04887E5B23522CD470243453A299FA9E77237716103ABC11A1DF38855ED6F2EE187E9C582BA6		0450863AD64A87AE8A2FE83C1AF1A8403CB53F53E486D8511DAD8A04887E5B23522CD470243453A299FA9E77237716103ABC11A1DF38855ED6F2EE187E9C582BA6
	2 - Perform SHA-256 hashing on the public key		2 - Perform [[SHA-256]] hashing on the public key
	600FFE422B4E00731A59557A5CCA46CC183944191006324A447BDB2D98D4B408		600FFE422B4E00731A59557A5CCA46CC183944191006324A447BDB2D98D4B408
	3 - Perform RIPEMD-160 hashing on the result of SHA-256		3 - Perform [[RIPEMD-160]] hashing on the result of SHA-256
	010966776006953D5567439E5E39F86A0D273BEE		010966776006953D5567439E5E39F86A0D273BEE
	4 - Add version byte in front of RIPEMD-160 hash (0x00 for Main Network)		4 - Add version byte in front of RIPEMD-160 hash (0x00 for Main Network)

Harding: Added Bitcoin Core documentation navbox

2015-08-17T16:05:53Z

Added Bitcoin Core documentation navbox

← Older revision		Revision as of 16:05, 17 August 2015
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	[[Category:Technical]]		[[Category:Technical]]

			{{Bitcoin Core documentation}}

Newar: link to HD

2015-01-21T11:04:35Z

link to HD

← Older revision		Revision as of 11:04, 21 January 2015
Line 4:		Line 4:
	A [[Bitcoin address]] is a 160-bit hash of the public portion of a public/private [[Wikipedia:Elliptic_Curve_DSA\|ECDSA]] keypair. Using [[Wikipedia:Public-key_cryptography\|public-key cryptography]], you can "sign" data with your [[private key]] and anyone who knows your public key can verify that the signature is valid.		A [[Bitcoin address]] is a 160-bit hash of the public portion of a public/private [[Wikipedia:Elliptic_Curve_DSA\|ECDSA]] keypair. Using [[Wikipedia:Public-key_cryptography\|public-key cryptography]], you can "sign" data with your [[private key]] and anyone who knows your public key can verify that the signature is valid.

	A new keypair is generated for each receiving address (with newer HD wallets, this is done deterministically).		A new keypair is generated for each receiving address (with newer [[Deterministic wallet \| HD wallets]], this is done deterministically).
	The public key and their associated private keys (or the seed needed to generate them) are stored in the [[wallet]] data file.		The public key and their associated private keys (or the seed needed to generate them) are stored in the [[wallet]] data file.
	This is the only file users should need to [[backup\|backup]].		This is the only file users should need to [[backup\|backup]].