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Transfer Transactions⚓︎

Transfer Transaction
A transaction that allows sending mosaics and optional messages from one account to another.

Transfer transactions are the most common type of transaction on Symbol, enabling both asset transfers and simple communication.

Key Features⚓︎

  • Mosaic Transfer

    You can attach one or more mosaics to a transfer transaction. All mosaics in a transfer transaction are sent from one sender to one recipient. This makes transfer transactions ideal for simple, direct asset transfers.

  • Message Support

    Optional plaintext or encrypted messages can be included. A transfer transaction does not require mosaics, so messages can also be sent on their own. This allows for simple communication alongside the mosaic transfers.

  • Aggregate Compatibility

    Multiple transfer transactions can be wrapped in an aggregate transaction, allowing multiple senders and multiple recipients in a single transaction.

  • Multisig Compatibility

    Transfer transactions, like all other transactions, support multisignature accounts. This allows them to require authorization from more than one account, allowing complex governance schemes.

Structure⚓︎

Besides the common transaction structure, a transfer transaction contains the following attributes:

Attribute Description
Recipient's address Address or namespace alias identifying the recipient.
List of transferred mosaics Zero or more mosaics to transfer.
Optional message Plaintext or encrypted message, up to 1024 bytes.

Recipient's Address⚓︎

The recipient can be specified as an address or a namespace alias.

Warning

It is possible to send mosaics to an address that has never appeared on-chain.

This behavior is normal and supported, but care must be taken to ensure the recipient controls the destination address, because if no one has the private key corresponding to it, the transferred mosaics will be permanently locked.

List of Transferred Mosaics⚓︎

This list includes the mosaic ID (or namespace alias) and number of units for each transferred mosaic.

Naturally, the sender must own enough units of each mosaic, or the transaction will be rejected.

The list may also be empty, allowing messages to be sent without transferring any assets.

Optional Message⚓︎

A message of up to 1024 bytes may be included in the transaction.

The Symbol protocol does not define a standard encoding for messages. It is up to the sender and recipient to agree on a format or encoding scheme (e.g., UTF-8, JSON, hex). By convention, most wallets and applications assume UTF-8 encoding.

Encryption Convention

In order to support encryption, applications built on top of Symbol developed a convention in which the first byte of the message indicates whether the rest is encrypted or not:

  • If the first byte is 0x00, the following bytes contain an unencrypted message.
  • If the first byte is 0x01, the following bytes contain a message encrypted using Bouncy Castle's AES block cipher in CBC mode and the recipient's public key, so that only the recipient can decrypt it.

Note that this prefix byte reduces the maximum message length to 1023 bytes.

This convention is supported by the Symbol Desktop Wallet, the Symbol Explorer, and many other applications, but it is not part of the Symbol protocol itself.