What is Grin?


Grin is a cryptocurrency focused on privacy, scalability and fungibility. Excitement exists around Grin in part due to the novel combination of privacy and scalability solutions introduced by the protocol upon which Grin is built - MimbleWimble. Beyond the technical innovations, tremendous interest in Grin exists due to the mysterious conditions surrounding its origins, its cultivation by a team of mostly anonymous developers and the fact that the only way to initially obtain Grin is through proof-of-work mining - all attributes that harken back to the original launch of Bitcoin. 


As a consequence of the privacy and scalability features introduced by MimbleWimble, Grin is transacted without the use of public addresses. Public addresses are the primary way an exchange like Poloniex passes cryptocurrencies back and forth with customers, so supporting an asset that doesn’t use public addresses required our engineers to come up with novel front and back end solutions. 


How to deposit Grin to Poloniex:


One of the unique characteristics of Grin that differentiates it from other coins is that there are no deposit addresses. Poloniex is currently the only exchange to offer two deposit methods in order to suit a variety of different use cases and to make Grin deposits as user-friendly and secure as possible. We hope that offering these two methods to choose from provides our customers with the greatest flexibility when deciding how to transfer their Grin into Poloniex.



Method

Description

Effort

Use Case

Method 1

URL deposit

Generates a unique URL that you can reuse whenever you send Grin into Poloniex. This method requires one, simple step to deposit.

Easy

Example: for users sending Grin to Poloniex from a mining pool or another exchange 

Method 2

File-based

Allows user to upload a JSON file containing raw transaction information; returns a signed response file that the sender can use to broadcast the final deposit transaction. This method requires both sender and receiver participation before the transaction is broadcast.

Advanced

Example: for users that want to generate their Grin transactions from scratch. This method is for more advanced users.


Method 1: URL deposits

This method allows the user to generate a unique URL that Grin coins can be sent to. Think of this URL like a standard cryptocurrency deposit address. This unique URL belongs to your Poloniex account and can be reused every time you would like to send Grin to Poloniex. 


The URL deposit process on Poloniex occurs in few simple steps:

  1. Navigate to the Balances, Deposits & Withdrawals page on the Poloniex website (Balances > Deposits & Withdrawals)

  2. Scroll down the page to Grin (GRIN) and tap Deposit

  3. Tap the View Deposit Address button



  1. A URL is generated and displayed on screen. This URL belongs uniquely to your account and can be reused whenever you send Grin into Poloniex.



  1. Use this URL to send Grin from your wallet. Once you have sent grins to Poloniex, you will be able to trade with your funds after 15 block confirmations.


Note: If you are sending grins from a mining pool or exchange that will withdraw to a grin URL, you can simply provide your Poloniex Grin URL. If you are sending grins from the Grin command line wallet, you may want to refer to Method 2 below in order to complete the transaction to Poloniex.


What’s actually happening

This deposit method reduces the interaction of sender and receiver into one action for the end user. Behind the scenes, the sending wallet generates a partial transaction file and sends it to the recipient wallet at an HTTP endpoint. The recipient adds their own information to the partial transaction and responds back to the sender with a signed response file. The sender finalizes the transaction using the file sent back by the receiver and broadcasts the transaction to a Grin node. This is all done in one synchronous step through an HTTP request. 


Method 2: File-based deposits

This method allows the user to upload a JSON file containing raw transaction information. Once successfully uploaded, Poloniex adds its own information to the message and downloads a signed response file back to the user. At this stage, the transaction may be finalized by the sender and broadcast to the Grin network.


The file-based deposit process on Poloniex occurs in a few simple steps:


  1. Navigate to the Balances, Deposits & Withdrawals page on the Poloniex website (Balances > Deposits & Withdrawals)

  2. Scroll down the page to Grin (GRIN) and tap Deposit

  3. Tap the Upload Partial Transaction File button



  1. Tap the Choose file button and select your partial transaction file from your device (accepted file format: JSON). Then, tap Upload.


Note: If you are stuck at this step of the process and need help generating a partial transaction file, please visit the Grin command line wallet guide on sending grins.

  1. Once you have uploaded your partial transaction file, we will sign your transaction and securely download it back to your device (this downloaded file is called a “signed response file”).



  1. You may now broadcast the finalized transaction, which will send the funds to your Poloniex Grin balance. If you are unsure about how to broadcast the final transactions, please read this guide on finalizing a Grin transaction in the wallet documentation. 


What’s actually happening

Unlike traditional cryptocurrency transactions, where money can be “pushed” to a public address, Grin transactions require interaction from both the sender and receiver before a transaction can be broadcast to the network. In the file-based method, the sender must form a “handshake” with Poloniex before the deposit into Poloniex starts. 


Frequently Asked Questions: 


How can I withdraw my Grin?

Please review our step-by-step instructions on how to withdraw Grin from Poloniex here! You can currently withdraw your Grin to an HTTP or HTTPS endpoint. This format is the one most commonly employed by exchanges and provides the smoothest withdrawal experience because file-transfer between sender and receiver is not employed.


Where is the deposit address for Grin on my Poloniex account?

One of the unique features about Grin that differentiates it from other coins is that there are no deposit addresses. Poloniex offers two deposit methods for transferring Grin onto the exchange: a URL Deposit method and a File-Based Deposit method. Please see the above section titled 'How to deposit Grin to Poloniex' for a detailed description of which method you should use.

What is a partial transaction file?

A partial transaction file is a JSON file that is generated by the sending wallet. Once your unique partial transaction file is successfully uploaded to Poloniex, we will generate a signed response file for you to download.

What is a signed response file?

When depositing Grin into Poloniex, a signed response file is a JSON file that is generated by Poloniex – the receiving wallet – after a unique partial transaction file has been uploaded. This file should then be sent back to the sender, who finalizes and posts the transaction to the listening Grin node. If the transaction is successfully posted to the Grin blockchain, the balances will reflect on the sender’s and recipient’s wallets after 15 blocks have been found. 


What happens if I lose my signed response file?

It is okay if you lose your signed response file as you are able to download this file again from your Poloniex account. Please sign in to your account and navigate to the Balances, Deposits & Withdrawals page. Scroll down the page to Grin (GRIN) and tap Deposit.


What is the smallest amount of Grin that can be deposited into Poloniex at one time?

0.1 Grin.

What is the minimum block confirmation time for Grin?

15 blocks, but we may adjust it without notice for security reasons.

Using the file upload method, how long will my completed deposit stay in pending?

Once you broadcast the finalized transaction, your deposit will show as “pending” on the History page until it has reached 15 block confirmations. After 15 confirmations, you may trade your grins on the exchange.


Is there a time limit on how long I can leave a deposit unfinalized when using the file transfer method?

No, there is no time limit. However, in certain circumstances we may clear away deposits that have not been finalized after 30 days.


Can I cancel my deposit?

Please submit a support ticket for all deposit cancellation inquiries. Please view our article on How do I open a support ticket? to learn more about our Support Center.

Is there a limit to the number of pending deposit transactions that I can make at any one time?

No.