Accounts
An "Account" in the XRP Ledger represents a holder of XRP and a sender of transactions. The core elements of an account are:
- An identifying address, such as
rf1BiGeXwwQoi8Z2ueFYTEXSwuJYfV2Jpn
. (This is a "classic address", as opposed to the X-Address format.) - An XRP balance. Some of this XRP is set aside for the Reserve.
- A sequence number, which helps make sure any transactions this account sends are applied in the correct order and only once each. To execute a transaction, the transaction's sequence number and its sender's sequence number must match. Then, as part of applying the transaction, the account's sequence number increases by 1. (See also: Basic Data Types: Account Sequence.)
- A history of transactions that affected this account and its balances.
- One or more ways to authorize transactions, possibly including:
- A master key pair intrinsic to the account. (This can be disabled but not changed.)
- A "regular" key pair that can be rotated.
- A signer list for multi-signing. (Stored separately from the account's core data.)
In the ledger's data tree, an account's core data is stored in the AccountRoot ledger object type. An account can also be the owner (or partial owner) of several other types of data.
Tip: An "Account" in the XRP Ledger is somewhere between the financial usage (like "bank account") and the computing usage (like "UNIX account"). Non-XRP currencies and assets aren't stored in an XRP Ledger Account itself; each such asset is stored in an accounting relationship called a "Trust Line" that connects two parties.
Creating Accounts
There is not a dedicated "create account" transaction. The Payment transaction automatically creates a new account if the payment sends XRP equal to or greater than the account reserve to a mathematically-valid address that does not already have an account. This is called funding an account, and creates an AccountRoot object in the ledger. No other transaction can create an account.
Caution: Funding an account does not give you any special privileges over that account. Whoever has the secret key corresponding to the account's address has full control over the account and all XRP it contains. For some addresses, it's possible that no one has the secret key, in which case the account is a black hole and the XRP is lost forever.
The typical way to get an account in the XRP Ledger is as follows:
-
Generate a key pair from a strong source of randomness and calculate the address of that key pair. (For example, you can use the wallet_propose method to do this.)
-
Have someone who already has an account in the XRP Ledger send XRP to the address you generated.
-
For example, you can buy XRP in a private exchange, then withdraw XRP from the exchange to the address you specified.
Caution: The first time you receive XRP at your own XRP Ledger address, you must pay the account reserve (currently 20 XRP), which locks up that amount of XRP indefinitely. In contrast, private exchanges usually hold all their customers' XRP in a few shared XRP Ledger accounts, so customers don't have to pay the reserve for individual accounts at the exchange. Before withdrawing, consider whether having your own account directly on the XRP Ledger is worth the price.
-
Addresses
Accounts in the XRP Ledger are identified by an address in the XRP Ledger's base58 format. The address is derived from the account's master public key , which is in turn derived from a secret key. An address is represented as a string in JSON and has the following characteristics:
- Between 25 and 35 characters in length
- Starts with the character
r
- Uses alphanumeric characters, excluding the number "
0
" capital letter "O
", capital letter "I
", and lowercase letter "l
" - Case-sensitive
- Includes a 4-byte checksum so that the probability of generating a valid address from random characters is approximately 1 in 2^32
Note: The XRP community has proposed an X-address format that "packs" a destination tag into the address. These addresses start with an
X
(for the mainnet) or aT
(for the testnet). Exchanges and wallets can use X-addresses to represent all the data a customer needs to know in one value. For more information, see the X-address format site and codec .The XRP Ledger protocol only supports "classic" addresses natively, but ripple-lib, RippleX Dev Kit , and many other tools support X-addresses too.
For more information, see Accounts and base58 Encodings.
Any valid address can become an account in the XRP Ledger by being funded. You can also use an address that has not been funded to represent a regular key or a member of a signer list. Only a funded account can be the sender of a transaction.
Creating a valid address is a strictly mathematical task starting with a key pair. You can generate a key pair and calculate its address entirely offline without communicating to the XRP Ledger or any other party. The conversion from a public key to an address involves a one-way hash function, so it is possible to confirm that a public key matches an address but it is impossible to derive the public key from the address alone. (This is part of the reason why signed transactions include the public key and the address of the sender.)
For more technical details of how to calculate an XRP Ledger address, see Address Encoding.
Special Addresses
Some addresses have special meaning, or historical uses, in the XRP Ledger. In many cases, these are "black hole" addresses, meaning the address is not derived from a known secret key. Since it is effectively impossible to guess a secret key from only an address, any XRP possessed by black hole addresses is lost forever.
Address | Name | Meaning | Black Hole? |
---|---|---|---|
rrrrrrrrrrrrrrrrrrrrrhoLvTp |
ACCOUNT_ZERO | An address that is the XRP Ledger's base58 encoding of the value 0 . In peer-to-peer communications, rippled uses this address as the issuer for XRP. |
Yes |
rrrrrrrrrrrrrrrrrrrrBZbvji |
ACCOUNT_ONE | An address that is the XRP Ledger's base58 encoding of the value 1 . In the ledger, RippleState entries use this address as a placeholder for the issuer of a trust line balance. |
Yes |
rHb9CJAWyB4rj91VRWn96DkukG4bwdtyTh |
The genesis account | When rippled starts a new genesis ledger from scratch (for example, in stand-alone mode), this account holds all the XRP. This address is generated from the seed value masterpassphrase which is hard-coded . |
No |
rrrrrrrrrrrrrrrrrNAMEtxvNvQ |
Ripple Name reservation black-hole | In the past, Ripple asked users to send XRP to this account to reserve Ripple Names. | Yes |
rrrrrrrrrrrrrrrrrrrn5RM1rHd |
NaN Address | Previous versions of ripple-lib generated this address when encoding the value NaN using the XRP Ledger's base58 string encoding format. | Yes |
Deletion of Accounts
The DeletableAccounts amendment (enabled 2020-05-08) made it possible to delete accounts.
To be deleted, an account must meet the following requirements:
- The account's
Sequence
number plus 256 must be less than the current Ledger Index. - The account must not be linked to any of the following types of ledger objects (as a sender or receiver):
Escrow
PayChannel
RippleState
Check
- The account must own fewer than 1000 objects in the ledger.
- The AccountDelete transaction must pay a special transaction cost equal to at least the owner reserve for one item (currently 5 XRP).
After an account has been deleted, it can be re-created in the ledger through the normal method of creating accounts. An account that has been deleted and re-created is no different than an account that has been created for the first time.
Warning: The AccountDelete transaction's transaction cost always applies when the transaction is included in a validated ledger, even if the transaction failed because the account does not meet the requirements to be deleted. To greatly reduce the chances of paying the high transaction cost if the account cannot be deleted, submit the transaction with fail_hard
enabled.
Unlike Bitcoin and many other cryptocurrencies, each new version of the XRP Ledger's public ledger chain contains the full state of the ledger, which increases in size with each new account. For that reason, you should not create new XRP Ledger accounts unless necessary. You can recover some of an account's 20 XRP reserve by deleting the account, but you must still destroy at least 5 XRP to do so.
Institutions who send and receive value on behalf of many users can use Source Tags and Destination Tags to distinguish payments from and to their customers while only using one (or a handful) of accounts in the XRP Ledger.
Transaction History
In the XRP Ledger, transaction history is tracked by a "thread" of transactions linked by a transaction's identifying hash and the ledger index. The AccountRoot
ledger object has the identifying hash and ledger of the transaction that most recently modified it; the metadata of that transaction includes the previous state of the AccountRoot
node, so it is possible to iterate through the history of a single account this way. This transaction history includes any transactions that modify the AccountRoot
node directly, including:
- Transactions sent by the account, because they modify the account's
Sequence
number. These transactions also modify the account's XRP balance because of the transaction cost. - Transactions that modified the account's XRP balance, including incoming Payment transactions and other types of transactions such as PaymentChannelClaim and EscrowFinish.
The conceptual transaction history of an account also includes transactions that modified the account's owned objects and non-XRP balances. These objects are separate ledger objects, each with their own thread of transactions that affected them. If you have an account's full ledger history, you can follow it forward to find the ledger objects created or modified by it. A "complete" transaction history includes the history of objects owned by a transaction, such as:
RippleState
objects (Trust Lines) connected to the account.DirectoryNode
objects, especially the owner directory tracking the account's owned objects.Offer
objects, representing the account's outstanding currency-exchange orders in the decentralized exchangePayChannel
objects, representing asynchronous payment channels to and from the accountEscrow
objects, representing held payments to or from the account that are locked by time or a crypto-condition.SignerList
objects, representing lists of addresses that can authorize transactions for the account by multi-signing.
For more information on each of these objects, see the Ledger Format Reference.
Address Encoding
Tip: These technical details are only relevant for people building low-level library software for XRP Ledger compatibility!
XRP Ledger addresses are encoded using base58 with the dictionary rpshnaf39wBUDNEGHJKLM4PQRST7VWXYZ2bcdeCg65jkm8oFqi1tuvAxyz
. Since the XRP Ledger encodes several types of keys with base58, it prefixes the encoded data with a one-byte "type prefix" (also called a "version prefix") to distinguish them. The type prefix causes addresses to usually start with different letters in base58 format.
The following diagram shows the relationship between keys and addresses:
The formula for calculating an XRP Ledger address from a public key is as follows. For the complete example code, see encode_address.js
. For the process of deriving a public key from a passphrase or seed value, see Key Derivation.
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Import required algorithms: SHA-256, RIPEMD160, and base58. Set the dictionary for base58.
'use strict'; const assert = require('assert'); const crypto = require('crypto'); const R_B58_DICT = 'rpshnaf39wBUDNEGHJKLM4PQRST7VWXYZ2bcdeCg65jkm8oFqi1tuvAxyz'; const base58 = require('base-x')(R_B58_DICT); assert(crypto.getHashes().includes('sha256')); assert(crypto.getHashes().includes('ripemd160'));
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Start with a 33-byte ECDSA secp256k1 public key, or a 32-byte Ed25519 public key. For Ed25519 keys, prefix the key with the byte
0xED
.const pubkey_hex = 'ED9434799226374926EDA3B54B1B461B4ABF7237962EAE18528FEA67595397FA32'; const pubkey = Buffer.from(pubkey_hex, 'hex'); assert(pubkey.length == 33);
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Calculate the RIPEMD160 hash of the SHA-256 hash of the public key. This value is the "Account ID".
const pubkey_inner_hash = crypto.createHash('sha256').update(pubkey); const pubkey_outer_hash = crypto.createHash('ripemd160'); pubkey_outer_hash.update(pubkey_inner_hash.digest()); const account_id = pubkey_outer_hash.digest();
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Calculate the SHA-256 hash of the SHA-256 hash of the Account ID; take the first 4 bytes. This value is the "checksum".
const address_type_prefix = Buffer.from([0x00]); const payload = Buffer.concat([address_type_prefix, account_id]); const chksum_hash1 = crypto.createHash('sha256').update(payload).digest(); const chksum_hash2 = crypto.createHash('sha256').update(chksum_hash1).digest(); const checksum = chksum_hash2.slice(0,4);
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Concatenate the payload and the checksum. Calculate the base58 value of the concatenated buffer. The result is the address.
const dataToEncode = Buffer.concat([payload, checksum]); const address = base58.encode(dataToEncode); console.log(address); // rDTXLQ7ZKZVKz33zJbHjgVShjsBnqMBhmN