Expand description

Encryption key management and secure hashing

The modules exported are all optional keying schemes that can be toggled with Cargo features.

The default symmetric scheme

Trees in the simplest case will use the UsernamePassword keying scheme, which provides a symmetric encryption mechanism.

Asymmetric schemes

To create a split key that allows differentiating between reader and writer keys, enable the cryptobox Cargo feature. This will allow you to use an asymmetric scheme to encrypt data in the storage segments of your tree, but keep the indexes symmetrically encrypted.

Hardware-bound encryption

Infinitree has native support for using a Yubikey’s Challenge-Response HMAC-SHA1 mode to encrypt the header of the tree, enabled by the yubikey Cargo feature.

To allow for configuring the Yubikey, the yubico_manager crate is re-exported.

Changing keys

Changing of the header key is supported through by creating a special key through ChangeHeaderKey::swap_on_seal constructor.

Because changing the internal keys might potentially require re-encrypting the entire archive in a way that’s not possible to do with the Infinitree library, the implementation of such a change is up to your specific use case.

For instance, let’s assume you crate a symmetrically keyed tree, then write data into the storage segment of it.

use infinitree::{*,
                 object::Writer, fields::VersionedMap, backends::Directory};

let key = UsernamePassword::with_credentials("username".to_string(),

let mut tree = Infinitree::<VersionedMap<String, ChunkPointer>>::open(

// get access to the custom `storage` segment of the tree
let mut writer = tree.storage_writer().unwrap();

// use the writer to write data
let ptr = writer.write(b"my precious secret").unwrap();

// then store it in the index
tree.index().insert("Gollum?".into(), ptr);

tree.commit("My first shenanigans");

Changing the internal key at this point to e.g. cryptobox::StorageOnly would mean that all existing data in the stash, referenced only through ChunkPointers is now inaccessible.

For the sake of straightforward use and space efficiency of chunk references, this is not permitted.


Asymmetric cryptography based encryption scheme for write-only trees.

Use a Yubikey to secure trees.


Change the header key on sealing a tree.

An incremental hash state that can accept any number of writes.

Binds header and internal encryption. This type can only be instantiated through type aliases.

A raw cryptographic key


Sealed trait to mark encryption schemes usable in Infinitree.

Type Definitions

A cryptographic hash of some data

Key source for all crypto operations.

HMAC generated by an AEAD scheme

Use a combination of username/password to locate and unlock a tree.