amnesia

amnesia is a command-line tool for sealing secrets with a set of questions, with a specified number of answers required to decrypt the secret. It uses argon2id and Shamir's Secret Sharing under the hood.

I've been thinking about how I would recover my digital life if I suffered from amnesia and forgot all my passwords. The idea behind amnesia is that I could seal a master password with a set of questions about my life I'd be able to answer even with memory loss, and use that master password to recover everything else.

How it works

Upon sealing a secret, the user is asked to provide a set of questions and answers, and a threshold. The threshold is the number of questions that must be answered correctly to unseal the secret, and must be at least 2. The user is prompted with test questions before sealing the secret to ensure they have been inputted correctly.

Demo

Installation

Brew

brew install cedws/tap/amnesia

Scoop

scoop bucket add cedws https://github.com/cedws/scoop-bucket.git
scoop install amnesia

Go

go install github.com/cedws/amnesia@latest

Usage

Sealing a secret

# Basic usage
echo "my-master-password" | amnesia seal -f sealed.json

# Seal without test questions
echo "my-master-password" | amnesia seal -f sealed.json -t

Unsealing a secret

# Basic usage
amnesia unseal -f sealed.json

# Unseal to output file
amnesia unseal -f sealed.json -o secret

For strong protection of the secret, enter a good number of difficult questions. An example usage could be to enter your last five passwords as questions.

Answers are used verbatim in key-derivation, so be mindful of usage of casing and punctuation.

age Plugin (experimental)

amnesia has experimental support for age as an identity plugin. amnesia can generate an age-compatible X25519 identity sealed with questions. When age wants to decrypt data using this identity, it will prompt the user for the required answers to unseal the identity.

To install amnesia as an age plugin, create a symlink in your PATH which links age-plugin-amnesia to amnesia. You can also just clone the binary. If you've installed amnesia via brew, you don't need to do anything.

ln -s amnesia age-plugin-amnesia
# OR (not recommended)
cp amnesia age-plugin-amnesia

To generate an age-compatible identity, run:

amnesia age-keygen

This will interactively prompt for questions to seal the identity with, and output something like this:

# created 2025-07-16T23:55:59+09:00
# public key: age1enfsyp6vug3l4xt65jysvlpl076xkw4cxup89rmteakfzre8uajqlnya3u
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

The public key is a "recipient" and can be shared with anyone. You can use it to encrypt data like so:

echo "secret" | age -r age1enfsyp6vug3l4xt65jysvlpl076xkw4cxup89rmteakfzre8uajqlnya3u > secret.enc

The long line beginning with AGE-PLUGIN-AMNESIA-... is the "identity." This is an encrypted X25519 key which can only be unsealed with sufficient answers to the input questions.

You can decrypt data with the identity like so:

age --decrypt -i identity.txt secret.enc

This will interactively prompt for answers via age.

Important

It is not currently possible to leave an answer blank due to an age limitation. You must provide the correct answer to all questions for successful decryption.

Cryptography

Warning

amnesia has not been cryptographically audited, use at your own risk. If you're interested in helping out with this, please get in touch.

The cryptography used in amnesia is argon2id, AES-CTR, AES-GCM and Shamir's Secret Sharing.

1. A 32 byte DEK (data encryption key) is generated
2. The DEK is split into N shares using Shamir's Secret Sharing, where N is the number of questions
3. A 32 byte KEK (key encryption key) is derived from each answer using argon2id KDF
4. Each share of the DEK is encrypted with an answer KEK using AES-CTR
5. The encrypted shares are stored alongside the corresponding questions
6. The secret is encrypted with the DEK using AES-GCM

This hybrid method of encrypting a secret with a DEK and splitting the DEK into parts with SSS means very large secrets can be protected with minimal overhead.