Transactions

Tx type #	Tx type name
1	Genesis Transaction
4	Transfer Transaction
8	Lease Transaction
9	Cancel Lease Transaction
11	Mass Transfer Transaction
12	Data Transaction
13	Set Script Transaction
15	Anchor Transaction
16	Association Transaction
17	Revoke Association Transaction
18	Sponsor Transaction
19	Cancel Sponsor Transaction
20	Register Transaction
21	Burn Transaction
22	Mapped Anchor Transaction
23	Statement Transaction
24	Certificate Transaction

Signing a transaction

The process is as follows: create a binary message for signing, then create a signature using the private key.

To validate a signature, the same binary message must be constructed. For this, the order of the fields matter, if you switch the order, the message will be different. The public key can be used for validation.

The binary message differs for each transaction type. Please check the documentation.

Example

Transaction data:

Field	Value
Sender address (not used, just for information)	3N9Q2sdkkhAnbR4XCveuRaSMLiVtvebZ3wp
Private key (used for signing, not in tx data)	7VLYNhmuvAo5Us4mNGxWpzhMSdSSdEbEPFUDKSnA6eBv
Public key	EENPV1mRhUD9gSKbcWt84cqnfSGQP5LkCu5gMBfAanYH
Recipient address	3NBVqYXrapgJP9atQccdBPAgJPwHDKkh6A8
Amount	1
Fee	1
Timestamp	1479287120875
Attachment (as byte array)	[1, 2, 3, 4]

Bytes:

#	Field name	Type	Position	Length	Value	Base58 bytes value
1	Transaction type (0x04)	Byte	0	1	4	5
2	Sender's public key	Bytes	1	32	...	EENPV1mRhUD9gSKbcWt84cqnfSGQP5LkCu5gMBfAanYH
3	Timestamp	Long	33	8	1479287120875	11frnYASv
4	Amount	Long	41	8	1	11111112
5	Fee	Long	49	8	1	11111112
6	Recipient's address	Bytes	57	26	...	3NBVqYXrapgJP9atQccdBPAgJPwHDKkh6A8
7	Attachment's length (N)	Short	83	2	4	15
8	Attachment's bytes	Bytes	85	N	[1,2,3,4]	2VfUX

Total data bytes for sign:

Ht7FtLJBrnukwWtywum4o1PbQSNyDWMgb4nXR5ZkV78krj9qVt17jz74XYSrKSTQe6wXuPdt3aCvmnF5hfjhnd1gyij36hN1zSDaiDg3TFi7c7RbXTHDDUbRgGajXci8PJB3iJM1tZvh8AL5wD4o4DCo1VJoKk2PUWX3cUydB7brxWGUxC6mPxKMdXefXwHeB4khwugbvcsPgk8F6YB

Signature of transaction data bytes (one of an infinite number of valid signatures):

2mQvQFLQYJBe9ezj7YnAQFq7k9MxZstkrbcSKpLzv7vTxUfnbvWMUyyhJAc1u3vhkLqzQphKDecHcutUrhrHt22D

Total transaction bytes with signature:

6zY3LYmrh981Qbzj7SRLQ2FP9EmXFpUTX9cA7bD5b7VSGmtoWxfpCrP4y5NPGou7XDYHx5oASPsUzB92aj3623SUpvc1xaaPjfLn6dCPVEa6SPjTbwvmDwMT8UVoAfdMwb7t4okLcURcZCFugf2Wc9tBGbVu7mgznLGLxooYiJmRQSeAACN8jYZVnUuXv4V7jrDJVXTFNCz1mYevnpA5RXAoehPRXKiBPJLnvVmV2Wae2TCNvweHGgknioZU6ZaixSCxM1YzY24Prv9qThszohojaWq4cRuRHwMAA5VUBvUs

Key type

By default, transactions are signed using the ED25519 algorithm. However, LTO supports multiple algorithms and curves like secp256k1, NIST P-256, and RSA. When broadcasting a transaction, it's required to include the key type in addition to the sender's public key.

RSA public keys are too large to store for each request. For RSA, the sender public key field must contain the SHA256 hash of the public key. This means that the transaction can't be validated by itself. RSA is only available through a smart account or by publishing an X.509 certificate to the public chain.

Proofs

Proofs are a flexible way to authorize a transaction. Each proof is a Base58 encoded byte string and can be a signature, a secret, or anything else – the semantics of the proof is dictated by the smart contract that interprets it. There can be up to 8 proofs at most 64 bytes each.

By default, only one proof is used, which must be the transaction signature by the sender. It should be the very first element in the proofs array, while all the other elements are ignored. The JSON looks like

"proofs": [ "21jgWvYq6XZuke2bLE8bQEbdXJEk..." ]

Transaction id

The transaction id is not stored in the transaction bytes. It's calculated from the binary message for signing as blake2b256(binary_message).