top of page
Blog article

Blog article

[PPAP Measures] Ready-to-use file transfer service YubiOn SecureFileTransfer

On November 30th, 2022, we released "YubiOn SecureFileTransfer (beta version)", a file transfer cloud service that can be used for PPAP countermeasures.

This time, I would like to introduce how actually to use "YubiOn SecureFileTransfer", including the procedure.

The first half is a rough overview, and the second half describes the actual procedure. So, if you want to know the outline, you can read only the first half.

※ At the time of this article, the beta version was used, so please understand that the operation and specifications may change due to future product updates.

[First half] YubiOn SecureFileTransfer Introduction

I will introduce the general features of YubiOn SecureFileTransfer.

PPAP headed for repeal

We are introducing it under the name of PPAP countermeasure product, but I think some people may be wondering: What exactly is PPAP? So let me briefly explain this.

For example, imagine a situation where you want to email someone a confidential file.

If it's a regular file, you can attach it. But it's a confidential file, so you can't just attach it to an email. It is very dangerous if the e-mail is stolen, it will be a leakage of information.

So, you compressed the file you want to send to a ZIP file with a password. Then, you attached the ZIP file to an email and send it. But you need to tell your recipient the decompression password. So you sent another email with only the password...

I'm sure many of you have used this method before.

PPAP Pattern

This method of telling the password after attaching the ZIP file with a password is commonly called PPAP. If you've done it before, you'll know that this procedure is quite cumbersome. Moreover, it has been pointed out that it is not effective as a security measure. Certainly, suppose there is a risk of your e-mail being stolen. In that case, even if you send the password with a separate email, there is a high possibility that both of them will be stolen after all, and you can imagine that "It may not be very effective?".

The Japanese government is also shifting toward prohibiting PPAP, and after November 26th, 2020, the Cabinet Office and Cabinet Secretariat announced that PPAP will be abolished.

The movement to abolish PPAP is also spreading among general companies. And it is expected to accelerate in the future. The use of password-protected ZIP files will become unusable for communication with those companies. Attaching a file to the email itself carries the risk of a computer virus, and in the future, if you attach a password-protected ZIP file, you may be scolded by your business partner as "Insane!".

What can YubiOn SecureFileTransfer do?

As mentioned above, PPAP and email attachments are becoming more and more discouraged. However, if you want to send a file in the middle of an email exchange, file attachments are very easy and convenient. If you can't use attachments, you may be in trouble.

This is where YubiOn SecureFileTransfer finally comes into play. This is a cloud service that allows you to send files securely without attaching them to emails.

Since it is not attached to the email, it is a PPAP countermeasure.

Let's take a look at an overview of the exchange.

Overview of communication using YubiOn SecureFileTransfer

Suppose someone who wants to send a file (sender) sends an email to someone who will receive the file (recipient).

※ The sender needs to register in advance to use YubiOn SecureFileTransfer, but here assume that registration has already been completed.

1. Upload file

First, the sender uploads the file he/she wants to send to YubiOn SecureFileTransfer.

At this time, he/she can specify the recipient's email address and can restrict people other than the specified email address from downloading the file.

※ You can choose not to specify an email address. In this case, there is no download limit; anyone can download the file.

2. Notify download URL

When the upload is complete, the download URL will be displayed, so email the URL to the person you want to send the file (recipient).

3. Download the file

The recipient accesses the download URL and downloads the file.

At this time, if an email address is specified, its owner will be asked to log in. Only specified accounts can download. If no email address is specified, you can download the file without logging in.

You have transferred the file successfully.

Advantages of YubiOn SecureFileTransfer

As you can see, exchanging files using YubiOn SecureFileTransfer does not attach files to emails.

In addition, you can specify an email address to prevent unauthorized file downloads by third parties. Therefore, even if a third party steals the content of the email, the file will not be.

Files are encrypted and stored in the cloud. In addition, the upload and download paths are encrypted with SSL/TLS, so files can be sent and received securely.

As with other functions, you can know whether uploaded files have been downloaded, and you can also delete uploaded files. As a result, if you delete the uploaded file after confirming the recipient's download, you can operate more safely without exposing the file more than necessary.

In the case of attaching to an email, if the destination email address or the attached file is incorrect, it may be irreversible. But if you use YubiOn SecureFileTransfer, you can delete the file. It also avoids the risk of these human errors.

In addition, since files to be uploaded can be up to 1GB, it can be used even when sending files that are too large to be attached by email.

You can use it free now, so please register and give it a try.

In the second half, I will introduce the specific operation procedure.


[Second half] How to use YubiOn SecureFileTransfer

YubiOn SecureFileTransfer is a cloud service that can be used immediately after registration.

This section describes the procedure for actually using the service to send and receive files.

The general flow of usage is as follows:

Now I will explain the specific steps.

Register for YubiOn SecureFileTransfer

Register an account to use YubiOn SecureFileTransfer.

Click the "Sign up" button on the top of the product page.

新規登録 - 注意事項

After reading the "Privacy Policy" and " Terms of Service", check the checkbox to agree and click the "Next" button.

Next, we will register an account. There are 2 ways:

[If you have a Google account]

If you have a Google account, you can easily register with your Google account.

Click the Google icon in "Register using an external service account".


If you use multiple Google accounts, please select which account to use.


Linking with Google is done and registration is complete.

This method is fast, right?

[If you don't have a Google account]

If you don't have a Google, you will need to register your email address and confirm your email.

Enter the name, email address, password, and confirmation password to be registered in "Register by entering user information" and click the register button at the bottom of the screen.

ユーザー登録 (手入力)

Click "OK" on the confirmation message.

The user's temporary registration screen will be displayed. At this time, a registration email will be sent to the email address you entered.


Check the email with your email client and click the link in the content.

The expiration time is 1 hour. If the expiration time has expired, you will have to start over from registration.


When you access the URL, an email address input screen opens Enter the registered email address, click the "Confirm" button, and enter the registered password to log in.


Enter the correct password to complete registration.


Upload the file you want to send

Log in to YubiOn SecureFileTransfer with your registered email address.

Select "Upload" from the left menu to open the Upload screen.


Enter the "Outline" items.



The sender's email address.

If you have multiple email addresses, you can add your email address in advance on the setting screen. Then, you can select from the pull-down menu.


This setting determines whether to specify the destination (recipient) email address.

If you select "Unlimited", anyone who knows the URL will be able to download the file. The recipients can download without registering for YubiOn SecureFileTransfer.


If you select "Only the specified mail address", enter the recipient's email address. You can also specify multiple email addresses by clicking the plus icon.

The recipient must log in to YubiOn SecureFileTransfer when downloading from the URL. ※ Registration is required if the recipient has not registered.

Selecting "Only the specified mail address" provides higher security strength, so it is usually safer to specify.



The file title when the uploaded file is downloaded. Any name is OK.


If you click the "Open options" button, the option settings will be displayed. But, since the setting value is fixed in the beta version, you cannot change it now.


Specify the file to be uploaded by clicking the "Select file" button in the "List of files in archive" or by dragging and dropping the file.

You can specify multiple files.


Click the "Upload" button and click "OK" on the confirmation message.

The file upload will start.

Files are automatically zipped and uploaded.


When the upload is completed, a screen like this will be displayed.

Send the download URL displayed here to the person you want to send the file.

We will send an email this time.

Notify the download URL to the recipient

To tell the download URL to the recipient, open the mailer and write the email text.


Copy and paste the download URL in the text.

The file download expiration date is set to 3 days by default, so write it just in case.

Send the email.

The sender operation is completed.

From the next step onwards, we will look at the operations on the recipient side.

Download the file

From here, we will check the operation on the recipient side.

An email has arrived from the sender, so click the download URL in the email text.


When you access the URL, the YubiOn SecureFileTransfer login screen will be displayed.

By the way, if the sender uploads without specifying an email address, the download screen will open directly instead of the login screen.


If you have registered for YubiOn SecureFileTransfer before, you will need to log in, but if you are using it for the first time, you will need to register by clicking the "Sign up" link.

The registration operation is the same as the content of "Register for YubiOn SecureFileTransfer" above, so I will omit it here. Please note that the registered email address must match the email address specified by the sender.

If the registration is successful, the received file screen will be displayed after login.

If the download screen is not displayed, open the received file screen from "Inbox" on the left menu.


The contents of the files are displayed in the "List of files in archive".

Click the "Download" button.

Click the "Save" button to download the file.


The file name is the name specified by the sender in the "Title".

The files have been successfully sent.

Introduction of other functions

I would like to add a function that allows the sender to check after uploading.

On the sender side, the information of the sent file is displayed in a list on the "Outbox" screen.


Click the title to view information about the uploaded file.


When you open the detailed information, you can check the URL of the download page again, so please check from here if you failed to copy the URL.

In addition, the number of times the file has been downloaded is displayed in the "Number of downloads possible", so you can check whether the file has been downloaded.

Currently, it is not possible to see who downloaded it, but we plan to make it possible to check detailed information in future updates.

By the way, if the download expiration date has passed, the file will be deleted and will disappear from the list, so please be careful.


  • YubiOn SecureFileTransfer is a service that allows you to transfer files without attaching them to emails.

  • It is a PPAP countermeasure because it does not attach files to the email.

  • Uploaded files are safe because you can limit who can download them.

That was the introduction of YubiOn SecureFileTransfer.

You can use it for free, so please take this opportunity to try it.

We will continue to update and aim to make the product even more convenient and easier to use.

If you have any comments or impressions, such as things you noticed while using the service, to suggestions for ways to use it, please send them from the "FeedBack" form that appears when you click your name in the upper right corner of the login.

We will use it as a reference for future updates.


Thank you for reading to the end.



bottom of page