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Security Center → Key Management

How Key Release Works

LifeWyn does not hand over plaintext. It waits for your rules, verifies the event, calculates recipient scope, and releases only encrypted key material that nominees unwrap locally.

Shamir Secret Sharing
Threshold you choose
GF(2^8) field
Key Rotation
Nominee Shares

Release Flow

From sealed vault to scoped nominee access

The release path is intentionally staged. Every step narrows risk before any wrapped key-shares are delivered.

1. A signal opens review
A missed protection check-in, verified incapacity report, death notice, or owner-defined emergency rule creates a case. The vault stays encrypted.
2. Verification package approved
Evidence, waiting periods, executor review, dispute holds, and jurisdiction notes must satisfy the rule set. Ambiguous cases pause instead of releasing.
3. Recipient scope is calculated
LifeWyn maps the approved event to the exact people, rooms, categories, and instructions you authorized. Unassigned vault areas remain sealed.
4. Wrapped key-shares are delivered
Nominees receive encrypted share envelopes and wrapped item keys, never plaintext content. Decryption happens on their device after local proof.

The server coordinates release, but cannot read the vault.

LifeWyn stores ciphertext, rule state, audit evidence, and encrypted key envelopes. The useful key material is reconstructed only when the configured threshold is met by authorized parties.

Release invariant

No approved case, no threshold, no local unwrap means no readable data.

How Threshold Sharing Works

A Threshold You Choose — No Single Point of Failure

Your vault key is split using Shamir's Secret Sharing. You pick how many shares exist and how many are needed; below is one common arrangement. No single party, including LifeWyn, holds enough material.

Your Device

Held in the OS key store; in a browser, in memory only

1 Share
1 of 5

Backup Device

Wrapped to your trusted device

1 Share
1 of 5

Nominee 1 (Spouse)

Encrypted for nominee's public key

1 Share
1 of 5

Nominee 2 (Child)

Encrypted for nominee's public key

1 Share
1 of 5

Trusted Contact

Encrypted for contact's public key

1 Share
1 of 5

Any threshold-many of these shares reconstruct the master key

LifeWyn stores encrypted share envelopes and audit state, not a usable plaintext share

Key Derivation Hierarchy

Master Key → Category Keys → Asset Keys

HKDF-SHA-256 with domain separation ensures cryptographic isolation between key types.

Level 0: Master Key (MK)

256-bit • scrypt(vault passphrase, salt, N=2^15, r=8, p=1)

Never leaves the device • In a browser it is held in memory for the session only

Vault Key (CK)

HKDF(MK, 'vault')

Root vault encryption

Credentials Key (CK)

HKDF(MK, 'credentials')

Password manager keys

Documents Key (CK)

HKDF(MK, 'documents')

Document encryption

Assets Key (CK)

HKDF(MK, 'assets')

Asset metadata keys

Bank Account

DEK = random 256-bit

Wrapped by Category Key

Insurance Policy

DEK = random 256-bit

Wrapped by Category Key

Will Document

DEK = random 256-bit

Wrapped by Category Key

Crypto Wallet

DEK = random 256-bit

Wrapped by Category Key

Property Deed

DEK = random 256-bit

Wrapped by Category Key

Investment

DEK = random 256-bit

Wrapped by Category Key

Medical Record

DEK = random 256-bit

Wrapped by Category Key

Digital Account

DEK = random 256-bit

Wrapped by Category Key

Cross-Device Sync

Secure Multi-Device Access

Your vault unlocks on every device without ever exposing the master key to our servers.

Device Enrollment
New device generates keypair. You approve via existing device (QR code or push notification).
  1. 1Generate device keypair
  2. 2Scan QR / approve push
  3. 3Receive wrapped master key
  4. 4Decrypt locally with biometric
Secure Sync
Vault changes encrypted with category keys. Sync via encrypted WebSocket. Conflict resolution via CRDTs.
  1. 1Encrypt change with category key
  2. 2Send ciphertext to server
  3. 3Push to other devices
  4. 4Decrypt & apply locally
Device Revocation
Lost device? Revoke instantly from any trusted device. Rotates affected keys.
  1. 1Mark device revoked
  2. 2Rotate device keypair
  3. 3Re-wrap shares for new key
  4. 4Push update to all devices

Key Rotation

Forward Secrecy Through Periodic Rotation

Category keys rotate annually. Asset keys rotate on modification. Compromised keys don't decrypt past data.

Key Type

Master Key

Frequency

Never (user-controlled)

Trigger

Manual password change only

Impact

Re-derives all category keys

Key Type

Category Keys

Frequency

Annually (automated)

Trigger

Time-based or security event

Impact

Re-wraps all DEKs in category

Key Type

Asset Keys (DEKs)

Frequency

On modification

Trigger

Content change detected

Impact

New DEK generated, old retired

Key Type

Device Keys

Frequency

30 days or on revocation

Trigger

Time-based or manual revoke

Impact

New device keypair generated

Key Type

Threshold Shares

Frequency

On key rotation

Trigger

Category/master key change

Impact

New Shamir polynomial generated

Your Keys. Your Control. Always.

LifeWyn never holds your master key. You decide who gets shares, when they rotate, and when to revoke.