Cryptan Easy Decription
In short,
this is a web service dedicated
to decrypting “p4c files” at
for those who want to decrypt them at.

ABOUT
This is a decryption-only web service that requires no login—simply access the website to use it.
You can decrypt files using just your email address.
*This service is a web service exclusively for “decrypting .p4c encrypted files.” It does not offer encryption or any other features.
*Decryption of personal encrypted files (.p4cx / .pqcx) or quantum-resistant encrypted files (.pqc) is not available.
Basic Information
| Service Type | Web Service |
|---|---|
| Price | Free |
| Sign up for the “ 4Login ” smartphone app | Not required |
| Installation of the Cryptan Software | Not required |
| Log in to the website | Not required |
| Sending and receiving files to/from the server | Yes |
| Supported Languages | Japanese / English |
Recommended System Requirements
Cryptan Easy Decription is a service designed for use on a PC.
Cryptan Easy Decription is compatible only with the latest versions of official browsers. We recommend updating your browser to the latest version before using the service.
Cryptan Easy Decription has been tested and confirmed to work in the following environments.
| OS | Browser |
|---|---|
| Windows 10/11 | Google Chrome Microsoft Edge |
| macOS | Google Chrome Safari |
Decryption Process
Decryption

- Open the website, drag an RSA-encrypted file onto the screen, and enter your email address.
- An identity verification email will be sent to the email address you entered; click the button in the email body.
- Click the “Start Decryption” button.
- Download the decrypted file.
The recipient verifies their identity by clicking the one-time URL sent to their email address, and the file sharing is complete.
