If you are looking for a way to use Citra as a portable application (keeping all your settings, save files, and AES keys in the same folder as the emulator), follow the steps below. Creating a Portable Citra Installation
By default, Citra saves its data in your user profile (e.g., AppData on Windows). To make it "portable": Locate your Citra executable (citra-qt.exe). In that same folder, create a new folder and name it user.
When Citra detects a folder named user in its root directory, it will store all configurations, shaders, and key files there instead of the global system folders. Where to Place aes_keys.txt
The aes_keys.txt file is required for Citra to decrypt and run encrypted .3ds or .cia ROMs. Portable Path: [Citra Folder]/user/sysdata/aes_keys.txt
Standard Path (Windows): %AppData%\Citra\sysdata\aes_keys.txt
Standard Path (macOS): ~/Library/Application Support/Citra/sysdata/aes_keys.txt How to Get the Keys
The legal and recommended way to obtain these keys is to dump them from your own 3DS console: Requirement: A 3DS with custom firmware (CFW) installed. Tools: Use GodMode9 and a specific dumpkeys.gm9 script.
Output: The script will generate the aes_keys.txt file on your SD card, which you can then copy to your Citra portable folder. Alternatives to Key Files
If you don't want to manage an aes_keys.txt file, you can use a Batch CIA 3DS Decryptor tool on your computer. This converts your encrypted games into decrypted files that Citra can play without needing external key files. Locating a decryption tool for your existing ROMs? citra aes keystxt portable
Setting up Citra on a specific platform like Steam Deck or Android?
Nintendo 3DS games are typically encrypted. While Citra can run decrypted ROMs without extra files, it requires system keys to handle encrypted formats like .3ds or .cia directly.
Decryption: The aes_keys.txt file contains the cryptographic keys needed to unlock game data.
Source: These keys are proprietary to Nintendo. Users are legally expected to dump them from their own physical 3DS hardware using tools like GodMode9.
Functionality: Without these keys, Citra will often report errors such as "Failed to load encrypted header" or simply fail to launch the game. Portable Mode vs. Standard Installation
Citra's behavior changes depending on how it handles its "User Directory" (where it stores saves, configuration, and keys).
Standard Path: On Windows, Citra usually stores system data in the roaming profile at %AppData%\Citra\sysdata\.
Portable Mode: To make Citra "portable" (running entirely from a single folder, such as on a USB drive), you must create a folder named user inside the same directory as the Citra executable (citra-qt.exe). If you are looking for a way to
Once this user folder exists, Citra ignores the AppData path and looks only within its own directory for data.
For portable setups, the key file must be placed in: [Citra Folder]\user\sysdata\aes_keys.txt. Implementation and Common Issues To properly set up the keys in a portable environment:
Extract Keys: Use a hacked 3DS and a script like dumpkeys.gm9 in GodMode9 to generate the aes_keys.txt.
Naming Convention: The file must be named exactly aes_keys.txt (all lowercase) for many systems, especially Linux-based ones like the Steam Deck, to recognize it.
Alternative: If managing keys is too complex, many users choose to use decrypted ROMs (often found in .3ds format), which bypass the need for an aes_keys.txt file entirely.
The Nintendo 3DS security architecture relies heavily on AES-128 encryption to protect proprietary content, including game cartridges (NCSD/NCCH), installed applications, and system archives. To facilitate the emulation of commercial software, Citra requires access to the console-specific AES key set to decrypt this content on-the-fly.
Historically, this was achieved via a manually created text file named aes_keys.txt. While modern implementations of Citra have automated this process via boot9.bin extraction, the "portable" nature of the aes_keys.txt file remains a critical fallback for legacy support and specific emulation scenarios.
aes_keys.txt Structure[Title keys]
titleID = key
[Common keys]
slot0x1BKey95 = 0123456789ABCDEF0123456789ABCDEF
slot0x18Key96 = FEDCBA9876543210FEDCBA9876543210 Step 3: The Directory Path The file structure
Part 7: Advanced Portable Setup – Full Decryption vs. On-the-Fly
Most users using "citra aes keystxt portable" are doing on-the-fly decryption. However, you can also permanently decrypt your ROMs using a tool like Batch CIA 3DS Decryptor (which also requires keys.txt).
| Feature | On-the-Fly (with keys.txt) | Permanent Decryption |
| :--- | :--- | :--- |
| Portable Size | Keys are small (few KB). | Decrypted ROMs are larger (but same size as encrypted). |
| Speed | Minimal overhead (AES-NI acceleration). | Faster loading (no decrypt step). |
| Compatibility | Works with all citra builds. | Works even without keys.txt. |
| Legality | Requires keys in memory. | Same legal requirement for initial decrypt. |
For a truly portable drive, using keys.txt is preferred. You keep encrypted ROMs (which are technically safer if you lose the USB drive) and only the tiny keyfile unlocks them.
Step 3: The Directory Path
The file structure should look like this:
Citra Folder/
│
├── citra-qt.exe
│
└── user/
│
└── sysdata/
│
└── aes_keys.txt
Crucial Detail: If the sysdata folder is missing inside the user folder, create it manually. It is case-sensitive (usually lowercase). Place your aes_keys.txt file inside sysdata.
Alternative: Using Decrypted ROMs
If you cannot obtain AES keys legally, you can use decrypted 3DS ROMs (already unpacked/decrypted via tools like Batch CIA 3DS Decryptor). Decrypted games run on Citra without any aes_keys.txt – but creating decrypted ROMs still requires access to keys or a hacked console.
Abstract
This paper explores the technical functionality of the aes_keys.txt file within the Citra Nintendo 3DS emulator environment. Specifically, it addresses the concept of "portability"—the ability to transfer this keyfile between different operating systems and Citra installations without loss of functionality. We examine the role of AES (Advanced Encryption Standard) keys in 3DS content decryption, the file format specifications, and the deprecation of manual key management in favor of automated hardware abstraction extraction.
What Is “txt portable”?
In emulation contexts, “txt portable” refers to a portable, ready-to-use aes_keys.txt file. This file is:
- A plain text document containing all necessary AES keys in a specific format.
- “Portable” means it can be copied/moved between different Citra installations (e.g., on USB drives, multiple PCs) without re-dumping keys.