Advanced Decentralized Blockchain Platform

Whitepaper Version: 2.0
TRON Protocol Version: 3.2

TRON DAO
December 10th, 2018, San Francisco

1. Introduction

4

1.1 Vision

4

1.2 Background4

1.3 History

5

1.4 Terminology

6

Address/Wallet

6

ABI

6

API

6

Asset

6

Bandwidth Points (BP)

6

Block

6

Block Reward

6

Block Header

6

Cold Wallet

7

DApp

7

gRPC

7

Hot Wallet

7

JDK

7

KhaosDB

7

LevelDB

7

Merkle Root

7

Public Testnet (Shasta)

8

RPC

8

Scalability

8

SUN

8

Throughput

8

Timestamp

8

TKC

8

TRC-108TRX

82. Architecture

9

2.1 Core

10

2.2 Storage

10

2.2.1 Blockchain Storage

10

2.2.2 State Storage

1012.3 Application

10

2.4 Protocol

11

2.4.1 Protocol Buffers

11

2.4.2 HTTP

11

2.5 TRON Virtual Machine (TVM)

11

2.6 Decentralized Exchange (DEX)

11

2.7 Implementation

12

3. Consensus
3.1 Delegated Proof of Stake (DPoS)
4. Account

13
13
16

4.1 Types

16

4.2 Creation

16

4.3 Structure

16

5. Block
5.1 Block Header

18
18

5.1.1 Raw Data

18

5.1.2 Witness Signature

19

5.1.3 Block ID

19

5.2 Transaction

19

5.2.1 Signing19

5.2.2 Bandwidth Model

19

5.2.3 Fee

20

5.2.4 Transaction as Proof of Stake (TaPoS)

20

5.2.5 Transaction Confirmation

21

5.2.6 Structure21

6. TRON Virtual Machine (TVM)

23

6.1 Introduction

23

6.2 Workflow

23

6.3 Performance25

6.3.1 Lightweight Architecture25

6.3.2 Robust25

6.3.3 High Compatibility

25

6.3.4 Low Cost

25

7. Smart Contract

26

7.1 Introduction

26

7.2 Energy Model26

7.3 Deployment272

7.4 Trigger Function

27

7.5 TRON Solidity27

8. Token28

8.1 TRC-10 Token

28

8.2 TRC-20 Token

28

8.3 Beyond

29

9. Governance30

9.1 Super Representative30

9.1.1 General30

9.1.2 Election30

9.1.3 Reward

30

a. Vote Reward

30

b. Block Reward

31

c. Reward Calculation

31

9.2 Committee

32

9.2.1 General

32

9.2.2 Dynamic Network Parameters32

9.2.3 Create Proposal

36

9.2.4 Vote Proposal

36

9.2.5 Cancel Proposal

36

9.3 Structure
10. DApp Development

36
37

10.1 APIs

37

10.2 Networks

37

10.3 Tools

37

10.4 Resources

37

11. Conclusion

393

1. Introduction
1.1 Vision
TRON is an ambitious project dedicated to the establishment of a truly decentralized Internet and its
infrastructure. The TRON Protocol, one of the largest blockchain-based operating systems in theworld, offers public blockchain support of high throughput, high scalability, and high availability for
all Decentralized Applications (DApps) in the TRON ecosystem. The July 2018 acquisition of
BitTorrent further cemented TRON’s leadership in pursuing a decentralized ecosystem.

1.2 Background
The introduction of Bitcoin in 2009 revolutionized society’s perception of the traditional financial
system in the wake of the Great Recession (2007-2008). As centralized hedge funds and banks
collapsed from speculation in opaque financial derivatives, blockchain technology provided atransparent universal ledger from which anybody could glean transaction information. The
transactions were cryptographically secured using a Proof of Work (PoW) consensus mechanism,
thus preventing double spend issues.
In late 2013, the Ethereum white paper proposed a network in which smart contracts and aTuring-complete Ethereum Virtual Machine (EVM) would allow developers to interact with the
network through DApps. However, as transaction volumes in Bitcoin and Ethereum peaked in 2017,it was apparent from the low transaction throughput times and high transaction fees thatcryptocurrencies like Bitcoin and Ethereum in their existing state were not scalable for widespread
adoption. Thus, TRON was founded and envisioned as an innovative solution to these pressing
scalability challenges.

4

1.3 History

The TRON DAO was established in July 2017 in Singapore. In December 2017, TRON had
launched its open source protocol. The Testnet, Blockchain Explorer, and Web Wallet were alllaunched by March 2018. TRON Mainnet launched shortly afterward in May 2018, marking theOdyssey 2.0 release as a technical milestone. In June 2018, TRON declared its independencewith the creation of the Genesis block, along with the July 2018 acquisition of BitTorrent. In
October 2018, TRON launched the TRON Virtual Machine (TVM), a complete developers’ toolset,
and 360 support system. The TRON roadmap involves combining BitTorrent’s 100 million users
with the TRON network via Project Atlas, as well as fostering the developer community to launch
exciting new DApps on the TRON network1.
1

V1.0 is available at https://tron.network/static/doc/white_paper_v_1_0.pdf

5

1.4 Terminology
Address/WalletAn address or wallet consisting of account credentials on the TRON network are generated by a
key pair, which consists of a private key and a public key, the latter being derived from the former
through an algorithm. The public key is usually used for session key encryption, signature
verification, and encrypting data that could be decrypted by a corresponding private key.
ABI
An application binary interface (ABI) is an interface between two binary program modules; usually
one of these modules is a library or an operating system facility, and the other is a user run
program.
API
An application programming interface (API) is mainly used for user clients development. With API
support, token issuance platforms can also be designed by developers themselves.
Asset
In TRON's documents, asset is the same as token, which is also denoted as TRC-10 token.
Bandwidth Points (BP)To keep the network operating smoothly, TRON network transactions use BP as fuel. Each accountgets 5000 free daily BP and more can be obtained by freezing TRX for BP. Both TRX and TRC-10
token transfers are normal transactions costing BP. Smart contract deployment and execution
transactions consume both BP and Energy.
Block
Blocks contain the digital records of transactions. A complete block consists of the magic number,block size, block header, transaction counter, and transaction data.
Block Reward
Block production rewards are sent to a sub-account (address/wallet). Super Representatives canclaim their rewards on Tronscan or through the API directly.
Block Header
A block header is part of a block. TRON block headers contain the previous block’s hash, theMerkle root, timestamp, version, and witness address.

6Cold Wallet
Cold wallet, also known as offline wallet, keeps the private key completely disconnected from any
network. Cold wallets are usually installed on "cold" devices (e.g. computers or mobile phones
staying offline) to ensure the security of TRX private key.
DApp
Decentralized Application is an App that operates without a centrally trusted party. An applicationthat enables direct interaction/agreements/communication between end users and/or resources
without a middleman.
gRPC
gRPC2 (gRPC Remote Procedure Calls) is an open source remote procedure call (RPC) system
initially developed at Google. It uses HTTP/2 for transport, Protocol Buffers as the interface
description language, and provides features such as authentication, bidirectional streaming and flow
control, blocking or nonblocking bindings, and cancellation and timeouts. It generates
cross-platform client and server bindings for many languages. Most common usage scenarios
include connecting services in microservices style architecture and connecting mobile devices, andbrowser clients to backend services.
Hot Wallet
Hot wallet, also known as online wallet, allows user's private key to be used online, thus it could besusceptible to potential vulnerabilities or interception by malicious actors.
JDK
Java Development Kit is the Java SDK used for Java applications. It is the core of Javadevelopment, comprising the Java application environment (JVM+Java class library) and Java
tools.
KhaosDB
TRON has a KhaosDB in the full-node memory that can store all the newly-forked chains generated
within a certain period of time and supports witnesses to switch from their own active chain swiftly
into a new main chain. See 2.2.2 State Storage for more details.
LevelDB
LevelDB was initially adopted with the primary goal to meet the requirements of fast R/W and rapid
development. After launching the Mainnet, TRON upgraded its database to an entirely customized
one catered to its very own needs. See 2.2.1 Blockchain Storage for more details.
Merkle Root
A Merkle root is the hash of all hashes of all transactions included as part of a block in a blockchain
network. See 3.1 Delegated Proof of Stake (DPoS) for more details.
2

https://en.wikipedia.org/wiki/GRPC

7

Public Testnet (Shasta)
A version of the network running in a single-node configuration. Developers can connect and test
features without worrying about the economic loss. Testnet tokens have no value and anyone canrequest more from the public faucet.
RPC3
In distributed computing, a remote procedure call (RPC) is when a computer program causes a
procedure (subroutine) to execute in a different address space (commonly on another computer ona shared network), which is coded as if it were a normal (local) procedure call, without the
programmer explicitly coding the details for the remote interaction.
Scalability
Scalability is a feature of the TRON Protocol. It is the capability of a system, network, or process tohandle a growing amount of work or its potential to be enlarged to accommodate that growth.
SUN
SUN replaced drop as the smallest unit of TRX. 1 TRX = 1,000,000 SUN.
Throughput
High throughput is a feature of TRON Mainnet. It is measured in Transactions Per Second (TPS),
namely the maximum transaction capacity in one second.
Timestamp
The approximate time of block production is recorded as Unix timestamp, which is the number ofmilliseconds that have elapsed since 00:00:00 01 Jan 1970 UTC.
TKC
Token configuration.
TRC-10A standard of crypto token on TRON platform. Certain rules and interfaces are required to follow
when holding an initial coin offering on TRON blockchain.
TRX
TRX stands for Tronix, which is the official cryptocurrency of TRON.

3

https://en.wikipedia.org/wiki/Remote_procedure_call8

2. Architecture
TRON adopts a 3-layer architecture divided into Storage Layer, Core Layer, and Application Layer.
The TRON protocol adheres to Google Protobuf, which intrinsically supports multi-language
extension.

Figure 1: TRON 3-layer Architecture92.1 Core
There are several modules in the core layer, including smart contracts, account management, andconsensus. A stack-based virtual machine is implemented on TRON and an optimized instruction
set is used. In order to better support DApp developers, Solidity4 was chosen as the smart contract
language, followed by future support of other advanced languages. In addition, TRON's consensus
mechanism is based on Delegated Proof of Stake (DPoS) and many innovations were made inorder to meet its unique requirements.

2.2 Storage
TRON designed a unique distributed storage protocol consisting of Block Storage and State
Storage. The notion of a graph database was introduced into the design of the storage layer tobetter meet the need for diversified data storage in the real world.

2.2.1 Blockchain Storage
TRON blockchain storage chooses to use LevelDB, which is developed by Google and provensuccessful with many companies and projects. It has high performance and supports arbitrary byte
arrays as both keys and values, singular get, put and delete, batched put and delete, bi-directional
iterators, and simple compression using the very fast Snappy algorithm.

2.2.2 State Storage
TRON has a KhaosDB in the full-node memory that can store all the newly forked chains generated
within a certain period of time and supports witnesses to switch from their own active chain swiftly
into a new main chain. It can also protect blockchain storage by making it more stable from being
terminating abnormally in an intermediate state.

2.3 Application
Developers can create a diverse range of DApps and customized wallets on TRON. Since TRON
enables smart contracts to be deployed and executed, the opportunities of utility applications are
unlimited.

4

Solidity official documentation: https://solidity.readthedocs.io/10

2.4 Protocol
TRON protocol adheres to Google Protocol Buffers5, which is a language-neutral, platform-neutral,and extensible way of serializing structured data for use in communications protocols, data storage,
and more.

2.4.1 Protocol Buffers
Protocol Buffers (Protobuf) is a flexible, efficient, automated mechanism for serializing structured
data, similar to JSON or XML, but much smaller, faster and simpler.
Protobuf (.proto) definitions can be used to generate code for C++, Java, C#, Python, Ruby,
Golang, and Objective-C languages through the official code generators. Various third-party
implementations are also available for many other languages. Protobuf eases development forclients by unifying the API definitions and also optimizing data transfers. Clients can take the API.proto from TRON’s protocol repository and integrate through the automatically-generated code
libraries.
As a comparison, Protocol Buffers is 3 to 10 times smaller and 20 to 100 times faster than XML,
with less ambiguous syntax. Protobuf generates data access classes that are easier to use
programmatically.

2.4.2 HTTP
TRON Protocol provides a RESTful HTTP API alternative to the Protobuf API. They share the sameinterface but the HTTP API can be readily used in javascript clients.

2.5 TRON Virtual Machine (TVM)
The TVM is a lightweight, Turing complete virtual machine developed for TRON’s ecosystem. The
TVM connects seamlessly with the existing development ecosystem to provide millions of global
developers with a custom-built blockchain system that is efficient, convenient, stable, secure, andscalable.

2.6 Decentralized Exchange (DEX)

5

Google Protocol Buffers official documentation: https://developers.google.com/protocol-buffers/

11

The TRON network natively supports decentralized exchange functions. A decentralized exchange
consists of multiple trading pairs. A trading pair (notation “Exchange”) is an Exchange Market
between TRC-10 tokens, or between a TRC-10 token and TRX. Any account can create a trading
pair between any tokens, even if the same pair already exists on the TRON network. Trading andprice fluctuations of the trading pairs follow the Bancor Protocol6. The TRON network stipulates thatthe weights of the two tokens in all trading pairs are equal, so the ratio of their balances is the pricebetween them. For example, consider a trading pair containing two tokens, ABC and DEF. ABC has
a balance of 10 million and DEF has a balance of 1 million. Since their weights are equal, 10 ABC =1 DEF. This means that the ratio of ABC to DEF is 10 ABC per DEF.

2.7 Implementation
The TRON blockchain code is implemented in Java and was originally a fork from EthereumJ.

6

Bancor Protocol official website: https://about.bancor.network/protocol/

123. Consensus
3.1 Delegated Proof of Stake (DPoS)
The earliest consensus mechanism is the Proof of Work (PoW) consensus mechanism. This
protocol is currently implemented in Bitcoin7 and Ethereum8. In PoW systems, transactions
broadcast through the network are grouped together into nascent blocks for miner confirmation. The
confirmation process involves hashing transactions using cryptographic hashing algorithms until amerkle root has been reached, creating a merkle tree:

Figure 2: 8 TRX transactions are hashed into the merkle root. This merkle root is then included in the block header, which
is attached to the previously confirmed blocks to form a blockchain. This allows for easy and transparent tracking oftransactions, timestamps, and other related information.

78

Bitcoin whitepaper: https://bitcoin.org/bitcoin.pdf
Ethereum whitepaper: https://github.com/ethereum/wiki/wiki/White-Paper

13Cryptographic hashing algorithms are useful in network attack prevention because they possess
several properties9:
●
●
●

●

●

●
●

Input/Output length size​ - The algorithm can pass in an input of any length in size, andoutputs a fixed length hash value.
Efficiency​ - The algorithm is relatively easy and fast to compute.
Preimage resistance​ - For a given output ​z,​ it is impossible to find any input ​x​ such thath(x) =​ ​z.​ In other words, the hashing algorithm ​h(x)​ is a one-way function in which only theoutput can be found, given an input. The reverse is not possible.
Collision resistance​ - It is computationally infeasible to find any pairs ​x1​ ≠​ ​ suchthat ​h(x1​ ​)​ x2​= h(x2​ )​ ​. In other words, the probability of finding two different inputs hashing to the same
output is extremely low. This property also implies ​second preimage resistance​.
Second preimage resistance​ - Given ​x​1​, and thus ​h(x​1​),​ it is computationally infeasible tofind any ​x​2​ such that ​h(x​1​) = h(x​2)​ ​. While this property is similar to ​collision resistance,​ theproperty differs in that it is saying an attacker with a given ​x1​ ​ will find it computationallyinfeasible to find any ​x2​ ​ hashing to the same output.
Deterministic​ - maps each input to one and only one output.
Avalanche effect​ - a small change in the input results in an entirely different output.

These properties give the cryptocurrency network its intrinsic value by ensuring attacks do notcompromise the network. When miners confirm a block, they are rewarded tokens as a built-in
incentive for network participation. However, as the global cryptocurrency market capitalization
steadily increased, the miners became centralized and focused their computing resources on
hoarding tokens as assets, rather than for network participation purposes. CPU miners gave way toGPUs, which in turn gave way to powerful ASICs. In one notable study, the total power
consumption of Bitcoin mining has been estimated to be as high as 3 GW10, comparable to Ireland’s
power consumption. This same study projected total power consumption to reach 8 GW in the near
future.
To solve the energy waste issue, the Proof of Stake (PoS) consensus mechanism was proposed bymany new networks. In PoS networks, token holders lock their token balances to become block
validators. The validators take turns proposing and voting on the next block. However, the problem
with standard PoS is that validator influence correlates directly to the amount of tokens locked up.
This results in parties hoarding large amounts of the network’s base currency wielding undue
influence in the network ecosystem.
The TRON consensus mechanism uses an innovative Delegated Proof of Stake system in which 27
Super Representatives (SRs) produce blocks for the network. Every 6 hours, TRX account holders
who freeze their accounts can vote for a selection of SR candidates, with the top 27 candidates
deemed the SRs. Voters may choose SRs based on criteria such as projects sponsored by SRs to
PAAR, C., PELZL, J., ​Understanding Cryptography: A Textbook for Students and Practitioners​, 2010 ed.
Springer-Verlag Berlin Heidelberg, 2010.
10https://www.sciencedirect.com/science/article/pii/S2542435118301776
9

14

increase TRX adoption, and rewards distributed to voters. This allows for a more democratized anddecentralized ecosystem. SRs’ accounts are normal accounts, but their accumulation of votes
allows them to produce blocks. With the low throughput rates of Bitcoin and Ethereum due to their
PoW consensus mechanism and scalability issues, TRON’s DPoS system offers an innovative
mechanism resulting in 2000 TPS compared to Bitcoin’s 3 TPS and Ethereum’s 15 TPS.
The TRON protocol network generates one block every three seconds, with each block awarding 32
TRX to Super Representatives. A total of 336,384,000 TRX will be awarded annually to the 27 SRs.
Each time an SR finishes block production, rewards are sent to a sub-account in the super-ledger.
SRs can check, but not directly make use of these TRX tokens. A withdrawal can be made by each
SR once every 24 hours, transferring the rewards from the sub-account to the specified SR
account.
The three types of nodes on the TRON network are Witness Node, Full Node, and Solidity Node.
Witness nodes are set up by SRs and are mainly responsible for block production and proposal
creation/voting. Full nodes provide APIs and broadcast transactions and blocks. Solidity nodes sync
blocks from other Full Nodes and also provide indexable APIs.

15

4. Account
4.1 Types
The three types of accounts in the TRON network are regular accounts, token accounts, andcontract accounts.
1. Regular accounts are used for standard transactions.
2. Token accounts are used for storing TRC-10 tokens.
3. Contract accounts are smart contract accounts created by regular accounts and can betriggered by regular accounts as well.

4.2 Creation
There are three ways to create a TRON account:
1. Create a new account through API
2. Transfer TRX into a new account address
3. Transfer any TRC-10 token into a new account address
An offline key-pair consisting of an address (public key) and a private key, and not recorded by the
TRON network, can also be generated. The user address generation algorithm consists ofgenerating a key-pair and then extracting the public key (64-byte byte array representing x, y
coordinates). Hash the public key using the SHA3-256 function (the SHA3 protocol adopted is
KECCAK-256) and extract the last 20 bytes of the result. Add 41 to the beginning of the byte arrayand ensure the initial address length is 21 bytes. Hash the address twice using SHA3-256 function
and take the first 4 bytes as verification code. Add the verification code to the end of the initialaddress and obtain the address in base58check format through base58 encoding. An encoded
Mainnet address begins with T and is 34 bytes in length.

4.3 Structure
The three different account types are Normal, AssetIssue, and Contract. An Account contains 7
parameters:
1. account_name​: the name for this account – e.g. BillsAccount.
2. type​: what type of this account is – e.g. 0 (stands for type ‘Normal’).
3. balance​: balance of this account – e.g. 4213312.

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4. vote​: received votes on this account – e.g. {(“0x1b7w…9xj3”,323),(“0x8djq…j12m”,88),…,(“0x82nd…mx6i”,10001)}.
5. asset​: other assets expected TRX in this account – e.g. {<“WishToken”, 66666>, <”Dogie”,
233>}.
6. latest_operation_time​: the latest operation time of this account.
Protobuf data structure:message​ ​Account​ {​message​ ​Vote​ {​bytes​ vote_address = ​1​;
​int64​ vote_count = ​2​;}​bytes​ accout_name = ​1​;
AccountType type = ​2​;​bytes​ address = ​3​;
​int64​ balance = ​4​;​repeated​ Vote votes = ​5​;
map<​string​, ​int64​> asset = ​6​;
​int64​ latest_operation_time = ​10​;}enum​ ​AccountType​ {Normal = ​0​;
AssetIssue = ​1​;
Contract = ​2​;}17

5. BlockA block typically contains a block header and several transactions.
Protobuf data structure:message​ ​Block​ {BlockHeader block_header = ​1​;​repeated​ Transaction transactions = ​2​;}

5.1 Block Header
A block header contains ​raw_data​, w​ itness_signature​, and ​blockID​.
Protobuf data structure:message​ ​BlockHeader​ {​message​ ​raw​ {​int64​ timestamp = ​1​;​bytes​ txTrieRoot = ​2​;​bytes​ parentHash = ​3​;
​uint64​ number = ​4​;
​uint64​ version = ​5​;​bytes​ witness_address = ​6​;}​bytes​ witness_signature = ​2​;​bytes​ blockID = ​3​;}

5.1.1 Raw Data
Raw data is denoted as ​raw_data​ in Protobuf. It contains the raw data of a message, containing 6
parameters:
1.
2.
3.
4.
5.

timestamp​: timestamp of this message – e.g. 1543884429000.
txTrieRoot​: the Merkle Tree’s Root – e.g. 7dacsa…3ed.
parentHash​: the hash of the last block – e.g. 7dacsa…3ed.
number​: the block height – e.g. 4638708.
version​: reserved – e​.g. 5.

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6. witness_address​: the address of the witness packed in this block – e.g. 41928c...4d21.

5.1.2 Witness Signature
Witness signature is denoted as ​witness_signature​ in Protobuf, which is the signature for thisblock header from the witness node.

5.1.3 Block ID
Block ID is denoted as ​blockID​ in Protobuf. It contains the atomic identification of a block. A Block
ID contains 2 parameters:
1. hash​: the hash of block.
2. number​: the hash and height of the block.

5.2 Transaction
5.2.1 Signing
TRON’s transaction signing process follows a standard ECDSA cryptographic algorithm, with a
SECP256K1 selection curve. A private key is a random number, and the public key is a point on theelliptic curve. The public key generation process consists of first generating a random number as a
private key, and then multiplying the base point of the elliptic curve by the private key to obtain the
public key. When a transaction occurs, the transaction raw data is first converted into byte format.
The raw data then undergoes SHA-256 hashing. The private key corresponding to the contract
address then signs the result of the SHA256 hash. The signature result is then added to thetransaction.

5.2.2 Bandwidth Model
Ordinary transactions only consume bandwidth points, but smart contract operations consume both
energy and bandwidth points. There are two types of bandwidth points available. Users can gain
bandwidth points from freezing TRX, while 5000 free bandwidth points are also available daily.
When a TRX transaction is broadcast, it is transmitted and stored in the form of a byte array overthe network. Bandwidth Points consumed by one transaction = number of transaction bytes
multiplied by bandwidth points rate. For example, if the byte array length of a transaction is 200,
then the transaction consumes 200 bandwidth points. However, if a TRX or token transfer results inthe target account being created, then only the bandwidth points consumed to create the accountwill be deducted, and additional bandwidth points will not be deducted. In an account creation
scenario, the network will first consume the bandwidth points that the transaction initiator gained

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from freezing TRX. If this amount is insufficient, then the network consumes the transaction
initiator’s TRX.
In standard TRX transfer scenarios from one TRX account to another, the network first consumes
the bandwidth points gained by the transaction initiator for freezing TRX. If that is insufficient, it thenconsumes from the free 5000 daily bandwidth points. If that is still not enough, then the network
consumes the TRX of the transaction initiator. The amount is calculated by the number of bytes inthe transaction multiplied by 10 SUN. Thus, for most TRX holders who may not necessarily freeze
their TRX to participate in SR voting, the first step is automatically skipped (since TRX balancefrozen = 0) and the 5000 daily free bandwidth powers the transaction.
For TRC-10 token transfers, the network first verifies whether the total free bandwidth points of theissued token asset are sufficient. If not, the bandwidth points obtained from freezing TRX are
consumed. If there is still not enough bandwidth points, then it consumes the TRX of the transaction
initiator.

5.2.3 Fee
TRON network generally does not charge fees for most transactions, however, due to system
restrictions and fairness, bandwidth usage and transactions do take in certain fees.
Fee charges are broken down into the following categories:
1. Normal transactions cost bandwidth points. Users can use the free daily bandwidth points(5000) or freeze TRX to obtain more. When bandwidth points are not enough, TRX will be
used directly from the sending account. The TRX needed is the number of bytes * 10 SUN.
2. Smart contracts cost energy (Section 6) but will also need bandwidth points for thetransaction to be broadcasted and confirmed. The bandwidth cost is the same as above.
3. All query transactions are free. It doesn’t cost energy or bandwidth.
TRON network also defines a set of fixed fees for the following transactions:
1. Creating a witness node: 9999 TRX
2. Issuing a TRC-10 token: 1024 TRX
3. Creating a new account: 0.1 TRX
4. Creating an exchange pair: 1024 TRX

5.2.4 Transaction as Proof of Stake (TaPoS)
TRON uses TaPoS to ensure the transactions all confirm the main blockchain, while making it
difficult to forge counterfeit chains. In TaPoS, the networks require each transaction include part of
the hash of a recent block header. This requirement prevents transactions from being replayed onforks not including the referenced block, and also signals the network that a particular user and their

20

stake are on a specific fork. This consensus mechanism protects the network against Denial ofService, 51%, selfish mining, and double spend attacks.

5.2.5 Transaction Confirmation
A transaction is included in a future block after being broadcast to the network. After 19 blocks aremined on TRON (including its own block), the transaction is confirmed. Each block is produced by
one of the top 27 Super Representatives in a round robin fashion. Each block takes ~3 seconds tobe mined on the blockchain. Time may slightly vary for each Super Representative due to network
conditions and machine configurations. In general, a transaction is considered fully confirmed after~1 minute.

5.2.6 Structure
Transaction APIs consist of the following functions:message​ ​Transaction​ {​message​ ​Contract​ {​enum​ ​ContractType​ {AccountCreateContract = ​0​; // Create account/wallet
TransferContract = ​1​; // Transfer TRX
TransferAssetContract = ​2​; // Transfer TRC10 token
VoteWitnessContract = ​4​; // Vote for Super Representative (SR)WitnessCreateContract = ​5​; // Create a new SR account
AssetIssueContract = ​6​; // Create a new TRC10 token
WitnessUpdateContract = ​8​; // Update SR information
ParticipateAssetIssueContract = ​9​; // Purchase TRC10 token
AccountUpdateContract = ​10​; // Update account/wallet information
FreezeBalanceContract = ​11​; // Freeze TRX for bandwidth or energy
UnfreezeBalanceContract = ​12​; // Unfreeze TRX
WithdrawBalanceContract = ​13​; // Withdraw SR rewards, once per day
UnfreezeAssetContract = ​14​; // Unfreeze TRC10 token
UpdateAssetContract = ​15​; // Update a TRC10 token’s information
ProposalCreateContract = ​16​; // Create a new network proposal by any SR
ProposalApproveContract = ​17​; // SR votes yes for a network proposal
ProposalDeleteContract = ​18​; // Delete a network proposal by owner
CreateSmartContract = ​30​; // Deploy a new smart contract
TriggerSmartContract = ​31​; // Call a function on a smart contract
GetContract = ​32​; // Get an existing smart contract
UpdateSettingContract = ​33​; // Update a smart contract’s parameters
ExchangeCreateContract = ​41​; // Create a token trading pair on DEX
ExchangeInjectContract = ​42​; // Inject funding into a trading pair

21

ExchangeWithdrawContract = ​43​; // Withdraw funding from a trading pairExchangeTransactionContract = ​44​; // Perform token trading
UpdateEnergyLimitContract = ​45​; // Update origin_energy_limit on asmart contract
}
}
}

22

6. TRON Virtual Machine (TVM)
6.1 Introduction
TRON Virtual Machine (TVM) is a lightweight, Turing complete virtual machine developed for the
TRON's ecosystem. Its goal is to provide a custom-built blockchain system that is efficient,convenient, stable, secure and scalable.
TVM initially forked from EVM11 and can connect seamlessly with the existing solidity smart contractdevelopment ecosystem. Based on that, TVM additionally supports DPoS consensus.
TVM employs the concept of Energy. Different from the Gas mechanism on EVM, operations oftransactions and smart contracts on TVM are free, with no TRX consumed. Technically, executablecomputation capacity on TVM is not restricted by total holding amount of tokens.

6.2 Workflow
The compiler first translates the Solidity smart contract into bytecode readable and executable on
the TVM. The TVM then processes data through opcode, which is equivalent to operating the logic
of a stack-based finite state machine. Finally, the TVM accesses blockchain data and invokes
External Data Interface through the Interoperation layer.

11

EVM: Ethereum Virtual Machine (https://github.com/ethereum/ethereumj)

23

Figure 3: TVM Workflow

24

6.3 Performance
6.3.1 Lightweight Architecture
TVM adopts a lightweight architecture with the aim of reducing resource consumption to guarantee
system performance.

6.3.2 Robust
TRX transfers and smart contract execution cost bandwidth points only, instead of TRX, which
exempts TRON from being attacked. Bandwidth consumption is predictable and static since eachcomputational step cost is fixed.

6.3.3 High Compatibility
TVM is compatible with EVM and will be compatible with more mainstream VMs in the future.
Thereby, all smart contracts on EVM are executable on TVM.

6.3.4 Low Cost
Due to TVM’s bandwidth setup, development costs are reduced and developers can focus on the
logic development of their contract code. TVM also offers all-in-one interfaces for contract
deployment, triggering and viewing to offer the convenience for developers.

25

7. Smart Contract
7.1 Introduction
A smart contract is a protocol that digitally verifies contract negotiation. They define the rules andpenalties related to an agreement and also automatically enforce those obligations. The smart
contract code facilitates, verifies, and enforces the negotiation or performance of an agreement ortransaction. From a tokenization perspective, smart contracts also facilitate automatic funds
transfers between participating parties should certain criteria be met.
TRON smart contracts are written in the Solidity language. Once written and tested, they can becompiled into bytecode, then deployed onto the TRON network for the TRON Virtual Machine. Once
deployed, smart contracts can be queried via their contract addresses. The contract Application
Binary Interface (ABI) shows the contract’s call functions and is used for interacting with the
network.

7.2 Energy Model
The maximum energy limit for deploying and triggering a smart contract is a function of several
variables:
●
●
●
●
●
●

Dynamic energy from freezing 1 TRX is 50,000,000,000 (Total Energy Limit) / (Total Energy
Weight)Energy limit is the daily account energy limit from freezing TRX
Remaining daily account energy from freezing TRX is calculated as Energy Limit - Energy
Used
Fee limit in TRX is set in smart contract deploy/trigger callRemaining usable TRX in the account
Energy per TRX if purchased directly (10 SUN = 1 Energy) = 100,000, SRs can vote on
adjustment

There are two consumption scenarios to calculate for maximum energy limit for deployment andtrigger. The logic can be expressed as follows:
const​ R = Dynamic Energy Limit
const​ F = Daily account energy ​from​ freezing TRX
const​ E = Remaining daily account energy ​from​ freezing TRX
const​ L = Fee limit ​in​ TRX set ​in​ deploy/trigger callconst​ T = Remaining usable TRX ​in​ account26

const​ C = Energy per TRX ​if​ purchased directly// Calculate M, defined as maximum energy limit for deployment/trigger ofsmart contractif​ F > L*R
let​ M = min(E+T*C, L*R)
elselet​ M = E+T*C

7.3 Deployment
When a TRON solidity smart contract is compiled, the TRON Virtual Machine reads the compiled
bytecode. The bytecode consists of a section for code deployment, contract code, and the Auxdata.
The Auxdata is the source code’s cryptographic fingerprint, used for verification. The deployment
bytecode runs the constructor function and sets up the initial storage variables. The deployment
code also calculates the contract code and returns it to the TVM. The ABI is a JSON file that
describes a TRON smart contract’s functions. This file defines the function names, their payability,
the function return values, and their state mutability.

7.4 Trigger Function
Once the TRON smart contracts are deployed, their functions can be triggered individually either via
TronStudio or through API calls. State-changing functions require Energy while read-only functions
execute without Energy.

7.5 TRON Solidity
TRON Solidity is a fork from Ethereum’s Solidity language. TRON modifies the original project tosupport TRX and SUN units (1 TRX = 1,000,000 SUN). The rest of the language syntax iscompatible with Solidity ^0.4.24. Thus the Tron Virtual Machine (TVM) is almost 100% compatible
with EVM instructions.

27

8. Token
8.1 TRC-10 TokenIn the TRON network, each account can issue tokens at the expense of 1024 TRX. ​To issue tokens,the issuer needs to specify a token name, the total capitalization, the exchange rate to TRX,
circulation duration, description, website, maximum bandwidth consumption per account, total
bandwidth consumption, and the amount of token frozen. Each token issuance can also configure
each account’s maximum daily token transfer Bandwidth Points, the entire network’s maximum daily
token transfer Bandwidth Points, total token supply, locking duration in days, and the total amountof tokens locked.

8.2 TRC-20 Token
TRC-20 is a technical standard used for smart contracts implementing tokens supported by the
TRON Virtual Machine. It is fully compatible with ERC-20.
The interface is as follows:
contract​ TRC20Interface {​function​ ​totalSupply​() ​public​ ​constant​ ​returns​ (uint);​function​ ​balanceOf​(address tokenOwner) ​public​ ​constant​ ​returns​ (uintbalance);​function​ ​allowance​(address tokenOwner, address spender) ​public​ ​constantreturns​ (uint remaining);​function​ ​transfer​(address to, uint tokens) ​public​ ​returns​ (bool success);​function​ ​approve​(address spender, uint tokens) ​public​ r​ eturns​ (boolsuccess);​function​ ​transferFrom​(address from, address to, uint tokens) ​public
returns​ (bool success);​event​ ​Transfer​(address indexed from, address indexed to, uint tokens);​event​ ​Approval​(address indexed tokenOwner, address indexed spender, uint
tokens);}From a developer’s perspective, there are several differences between TRC-10 and TRC-20. Someof the key differences are that TRC-10 tokens are accessible by APIs and smart contracts while
TRC-20 tokens allow for interface customization but are only accessible within smart contracts.

28

From a cost perspective, TRC-10 tokens have transaction fees that are 1000 times lower thanTRC-20, but carry bandwidth costs for API transfers and deposits. Transfers and deposits in smart
contracts for TRC-10 tokens cost both bandwidth and energy.

8.3 Beyond
Since TRON uses the same Solidity version as Ethereum, more token standards could be readily
ported to TRON.

29

9. Governance
9.1 Super Representative
9.1.1 General
Every account in the TRON network can apply and have the opportunity to become a Super
Representative (denoted as SR). Everyone can vote for SR candidates. The top 27 candidates withthe most votes will become SRs with the right and obligation to generate blocks. The votes arecounted every 6 hours and the SRs will change accordingly.
To prevent malicious attacks, there is a cost to becoming an SR candidate. When applying, 9999
TRX will be burned from the applicant’s account. Once successful, such account can join the SR
election.

9.1.2 Election
TRON Power (denoted as TP) is needed to vote and the amount of TP depends on the voter’s
frozen assets (TRX).
TP is calculated in the following way:

1 T P = 1 T RX f rozen to get bandwidth
Every account in the TRON network has the right to vote for their own SRs.
After the release (unfreeze, available after 3 days), users won't have any frozen assets and lose all
TP accordingly. As a result, all votes become invalid for the ongoing and future voting round unless
TRX is frozen again to vote.
Note that the TRON network only records the most recent vote, which means that every new votewill negate all previous votes.

9.1.3 Reward
a. Vote Reward30

Also known as Candidate Reward, which the top 127 candidates updated once every round (6hours) will share 115,200 TRX as mined. The reward will be split in accordance with the vote weight
each candidate receives. Each year, the total reward for candidates will be 168,192,000 TRX.
Total vote reward per roundWhy 115,200 TRX every round?

115, 200 T RX = total vote reward per round (V R/round)
V R/round = 16 T RX/block × 20 blocks/min × 60 mins/hr × 6 hrs/round
Notice: this is set by WITNESS_STANDBY_ALLOWANCE = 115,200 TRX. See dynamic network parameters.

Total vote reward per year
Why 168,192,000 TRX every year?

168, 192, 000 T RX = total vote reward per year (V R/year)
V R/year = 115, 200 T RX/round × 4 rounds/day × 365 days/year
b. Block Reward
Also known as Super Representative Reward, which the top 27 candidates (SRs) who are elected
every round (6 hours) will share roughly 230,400 TRX as mined. The reward will be split evenly
between the 27 SRs (minus the total reward blocks missed due to network error). A total of
336,384,000 TRX will be awarded annually to the 27 SRs.
Total block reward per roundWhy 230,400 TRX every round?

230, 400 T RX = total block reward per round (BR/round)
BR/round = 32 T RX/bloc × 20 blocks/min × 60 mins/hr × 6 hrs/round
Notice: the unit block reward is set by WITNESS_PAY_PER_BLOCK = 32 TRX. See dynamic network
parameters.

Total block reward per year
Why 336,384,000 TRX every year?

336, 384, 000 T RX = total block reward per year (BR/year)
BR/year = 230, 400 T RX/round × 4 rounds/day × 365 days/year
January 1, 2021
There will be no inflation on the TRON network before January 1, 2021, and the TRON DAO willaward all block rewards and candidate rewards prior to that date.

c. Reward Calculation31

SR reward calculation

total reward = vote reward (V R) + block reward (BR)candidate received
V R = total V R × votes SR total
votes
total BR− block missed × 32
27
Note: the reward is calculated per SR per round (6 hours)

BR =Rank 28 to rank 127 SR candidate reward calculation

total reward = vote reward (V R)
candidate received
V R = total V R × votes SR total
votes
Note: the reward is calculated per SR candidate per round (6 hours)

9.2 Committee
9.2.1 General
The committee is used to modify TRON dynamic network parameters, such as block generation
rewards, transaction fees, etc. The committee consists of the 27 SRs in the current round. Each SR
has the right to propose and vote on proposals. When a proposal receives 19 votes or more, it isapproved and the new network parameters will be applied in the next maintenance period (3 days).

9.2.2 Dynamic Network Parameters
0. MAINTENANCE_TIME_INTERVAL
a. Description
Modify the maintenance interval time in ms. Known as the SR vote interval time perround.
b. Example[6 * 3600 * 1000] ms - which is 6 hours.
c. Range[3 * 27* 1000, 24 * 3600 * 1000] ms
1. ACCOUNT_UPGRADE_COST
a. Description
Modify the cost of applying for SR account.
b. Example[9,999,000,000] SUN - which is 9,999 TRX.
c. Range[0,100 000 000 000 000 000] SUN
2. CREATE_ACCOUNT_FEE
a. Description
Modify the account creation fee.

32

3.

4.

5.

6.

7.

b. Example[100,000] SUN - which is 1 TRX.
c. Range[0,100 000 000 000 000 000] SUN
TRANSACTION_FEE
a. Description
Modify the amount of fee used to gain extra bandwidth.
b. Example[10] SUN/byte.
c. Range[0,100 000 000 000 000 000] SUN/byte
ASSET_ISSUE_FEE
a. Description
Modify asset issuance fee.
b. Example[1024,000,000] SUN - which is 1024 TRX.
c. Range[0,100 000 000 000 000 000] SUN
WITNESS_PAY_PER_BLOCK
a. Description
Modify SR block generation reward. Known as unit block reward.
b. Example[32,000,000] SUN - which is 32 TRX.
c. Range[0,100 000 000 000 000 000] SUN
WITNESS_STANDBY_ALLOWANCE
a. Description
Modify the rewards given to the top 127 SR candidates. Known as total vote reward
per round.
b. Example[115,200,000,000] SUN - which is 115,200 TRX.
c. Range[0,100 000 000 000 000 000] SUN
CREATE_NEW_ACCOUNT_FEE_IN_SYSTEM_CONTRACT
a. Description
Modify the cost of account creation. Combine dynamic network parameters #8 to get
total account creation cost:
C REAT E_N EW _ACCOU N T _F EE_IN _SY ST EM _CON T RACT × C REAT E_N EW _ACCOU N T _BAN DW IDT H_RAT E

b. Example[0] SUN.
c. Range[0,100 000 000 000 000 000] SUN
8. CREATE_NEW_ACCOUNT_BANDWIDTH_RATE

33

a. Description
Modify the cost of account creation. Combine dynamic network parameters #7 to get
total account creation cost:
C REAT E_N EW _ACCOU N T _F EE_IN _SY ST EM _CON T RACT × C REAT E_N EW _ACCOU N T _BAN DW IDT H_RAT E

b. Example[1].
c. Range[0,100,000,000,000,000,000]
9. ALLOW_CREATION_OF_CONTRACTS
a. Description
To turn on Tron Virtual Machine (TVM).
b. Example
True - set to activate and effect since 10/10/2018 23:47 UTC.
c. Range
True/False
10. REMOVE_THE_POWER_OF_THE_GR
a. Description
Remove the initial GR genesis votes
b. Example
True - effected at 11/4/2018 08:46 UTC.
c. Range
True/False - Notice: cannot set back to False from True.
11. ENERGY_FEE
a. Description
Modify the fee of 1 energy.
b. Example
20 SUN.
c. Range[0,100 000 000 000 000 000] SUN
12. EXCHANGE_CREATE_FEE
a. Description
Modify the cost of trading pair creation. Known as the cost of creating a trade order.
b. Example[1,024,000,000] SUN - which is 1024 TRX.
c. Range[0,100 000 000 000 000 000] SUN
13. MAX_CPU_TIME_OF_ONE_TX
a. Description
Modify the maximum execution time of one transaction. Known as the timeout limit of
one transaction.
b. Example
50 ms.
c. Range34[0, 1000] ms
14. ALLOW_UPDATE_ACCOUNT_NAME
a. Description
Modify the option to let an account update their account name.
b. Example
False - which is available to propose from java-tron Odyssey v3.2.
c. Range
True/False - Notice: cannot set back to False from True.
15. ALLOW_SAME_TOKEN_NAME
a. Description
Modify the validation of allowing different token have a duplicate name.
b. Example
False - which is available to propose from java-tron Odyssey v3.2.
c. Range
True/False - Notice: cannot set back to False from True.
16. ALLOW_DELEGATE_RESOURCE
a. Description
Modify the validation of allowing to issue token with a duplicate name, so thetokenID​ of the token, in long integer data type, would be the only atomic
identification of a token.
b. Example
False - which is available to propose from java-tron Odyssey v3.2.
c. Range
True/False - Notice: cannot set back to False from True.
17. TOTAL_ENERGY_LIMIT
a. Description
Modify the whole network total energy limit.
b. Example[50,000,000,000,000,000] SUN - which is 50,000,000,000 TRX.
c. Range[0,100,000,000,000,000,000] SUN
18. ALLOW_TVM_TRANSFER_TRC10
a. Description
Allow TRC-10 token transfer within smart contracts.
ALLOW_UPDATE_ACCOUNT_NAME, ALLOW_SAME_TOKEN_NAME,ALLOW_DELEGATE_RESOURCE proposals must all be approved before proposing
this parameter change.
b. Example
False - which is available to propose from java-tron Odyssey v3.2.
c. Range
True/False - Notice: cannot set back to False from True.

35

9.2.3 Create Proposal
Only the SR accounts have the rights to propose a change in dynamic network parameters.

9.2.4 Vote Proposal
Only committee members (SRs) can vote for a proposal and the member who does not vote in time
will be considered as a disagree. The proposal is active for 3 days after it is created. The vote canbe changed or retrieved during the 3-days voting window. Once the period ends, the proposal will
either succeed (19+ votes) or fail (and end).

9.2.5 Cancel Proposal
The proposer can cancel the proposal before it becomes effective.

9.3 Structure
SRs are the witnesses of newly generated blocks. A witness contains 8 parameters:
1. address​: the address of this witness – e.g. 0xu82h…7237.
2. voteCount​: number of received votes on this witness – e.g. 234234.
3. pubKey​: the public key for this witness – e.g. 0xu82h…7237.
4. url​: the url for this witness – e.g. https://www.noonetrust.com.
5. totalProduced​: the number of blocks this witness produced – e.g. 2434.
6. totalMissed​: the number of blocks this witness missed – e.g. 7.
7. latestBlockNum​: the latest height of block – e.g. 4522.
8. isjobs​: a boolean flag.
Protobuf data structure:message​ ​Witness​{​bytes​ address = ​1​;
​int64​ voteCount = ​2​;​bytes​ pubKey = ​3​;​string​ url = ​4​;
​int64​ totalProduced = ​5​;
​int64​ totalMissed = ​6​;
​int64​ latestBlockNum = ​7​;​bool​ isJobs = ​8​;}36

10. DApp Development
10.1 APIs
The TRON network offers a wide selection of over 60+ HTTP API gateways for interacting with the
network via Full and Solidity Nodes. Additionally, TronWeb is a comprehensive JavaScript library
containing API functions that enable developers to deploy smart contracts, change the blockchain
state, query blockchain and contract information, trade on the DEX, and much more. These API
gateways can be directed towards a local privatenet, the Shasta testnet, or the TRON Mainnet.

10.2 Networks
TRON has both a Shasta testnet as well as a Mainnet. Developers may connect to the networks bydeploying nodes, interacting via TronStudio, or using APIs via the TronGrid service. The TronGrid
service consists of load balanced node clusters hosted on AWS servers worldwide. As DAppdevelopment scales up and API call volumes increase, TronGrid successfully fields the increase in
API traffic.

10.3 Tools
TRON offers a suite of development tools for enabling developers to create innovative DApps.
TronBox is a framework that allows developers to test and deploy smart contracts via the TronWeb
API. TronGrid is a load balanced and hosted API service that allows developers to access the
TRON network without having to run their own node. TronGrid offers access to both the Shasta
testnet as well as the TRON Mainnet. TronStudio is a comprehensive Integrated Development
Environment (IDE) that enables developers to compile, deploy, and debug their Solidity smart
contracts. TronStudio contains an internal full node that creates a private local environment for
smart contract testing prior to deployment. The TronWeb API library connects developers to the
network via a wide selection of HTTP API calls wrapped in JavaScript.

10.4 Resources
The TRON Developer Hub is a comprehensive API documentation12 site tailored towards
developers wishing to build on the TRON network. The Developer Hub provides a high-level
conceptual understanding of TRON and walks users through the details of interacting with the12

Developer Hub: https://developers.tron.network/

37

network. The guides walk developers through node setup, deployment and interaction with smart
contracts, API interaction and implementation, building sample DApps, and using each of thedeveloper tools. Additionally, developer community channels are available through Discord13.

13

Discord: https://discordapp.com/invite/GsRgsTD

38

11. Conclusion
TRON is a scalable blockchain solution that has employed innovative methods for tacklingchallenges faced by legacy blockchain networks. Having reached over 2M transactions per day,with over 700K TRX accounts, and surpassing 2000 TPS, TRON has enabled the community increating a decentralized and democratized network.

39