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Gordian Envelope Use Cases: Financial Industry (including Self-Sovereign Assets)

In the financial industry, Gordian Envelopes can be used to encode and transmit sensitive financial information while preserving their complex data structures and ensuring privacy. This can include personally controlled (self-sovereign) assets such as seeds and keys as well as corporate assets such as contracts, transaction records, and audit reports. Gordian Envelopes offer protection for these assets not just through their ability to encrypt data, but also through their ability to elide or externally reference only certain parts of the Envelope. This can support both fair competition and cooperation in the financial industry through the use of progressive trust and selective disclosure.

For example, two financial institutions collaborating on a project could use Gordian Envelopes to share the information they need for the project, while still protecting their competitive advantage and keeping their data secure. Alternatively, an individual could encrypt his most sensitive information (such as a seed) while maintaining other referential data unencrypted.

The ability of Gordian Envelopes to have different recipients open them in different ways is also useful in the financial industry, because it allows different parties to access the information for different purposes. For example, financial institutions could share data with aligned partners, each of whom have their own private keys, while an individual protecting their personal assets could back it up himself with a secret sharding scheming while also giving a secondary key to his attorney.

Overall, Gordian Envelopes offer a flexible and privacy-enhancing solution for the transmission and storage of sensitive financial information.

Financal Use Cases Table of Contents

The following set of use cases currently focuses on using Gordian Envelopes to protect digital assets controlled in an individual, self-sovereign way. They are presented progressively: each use case builds on the previous one by demonstrating a new capability. They all refer to the same user (Sam) with the same self-sovereign storage needs.

Gordian Envelopes are powerful for the self-sovereign control of assets because they provide storage that is both resilient and secure. The security comes from the use of encryption in Envelopes while the resilience comes from Gordian Envelope's versatility in deciding what's encrypted and what's not, its ability to store high amounts of metadata, and its system of permits, which allow Envelopes to be opened in a wide variety of ways.

Part One: Self-Sovereign Storage of Secrets

This first set of progressive use cases demonstrates how to store secret information, how to improve resilience with metadata, how to improve privacy with salting, and how to improve security with wrapped encryption.

#1: Sam Stores a Secret (Secure Storage with Metadata)

Problem Solved: Sam wants to securely and resiliently store data that he personally controls.

Sam has too many keys! In order to organize them in a secure way, he plans to place each private key in an encrypted Gordian Envelope, indexed by the pubkey. But, he'll go beyond that and also add metadata to the secure storage mechanism; this will allow him to rebuild the private key if he loses the symmetric key he used to encrypt the Envelope!

The basic Gordian Envelope just combines the key's xpub as its subject with its xprv as an object:

"xpub6CiXsHfXkeXW2GBijsfihd64i8nebEWgxTxEq7j2ntT3GpyGKrP4v6dnz7ZNiZufVavY6pPwLTvdiUWSFD7tbCMpb3dvkpUqPiMdh4BRrso" [
    "xprv": "xprv9yjBTn8dvGyCon7Fdr8iLV9LA6xABmnqbF2e2jKREYv4Q2e7nK4pNJKK8qrLMJNKHrNTyHUatP7TepCeTHPWv64HQShKfy6eNxUzDgStSBg"
]

graph LR
    1(("5226a748<br/>NODE"))
    2["45c35879<br/>#quot;xpub6CiXsHfX...#quot;"]
    3(["2cc2fa4f<br/>ASSERTION"])
    4["d737f2ff<br/>#quot;xprv#quot;"]
    5["6ae4c8df<br/>#quot;xprv9yjBTn8d...#quot;"]
    1 -->|subj| 2
    1 --> 3
    3 -->|pred| 4
    3 -->|obj| 5
    style 1 stroke:red,stroke-width:3.0px
    style 2 stroke:#55f,stroke-width:3.0px
    style 3 stroke:red,stroke-width:3.0px
    style 4 stroke:#55f,stroke-width:3.0px
    style 5 stroke:#55f,stroke-width:3.0px
    linkStyle 0 stroke:red,stroke-width:2.0px
    linkStyle 1 stroke-width:2.0px
    linkStyle 2 stroke:green,stroke-width:2.0px
    linkStyle 3 stroke:#55f,stroke-width:2.0px
Loading

Sam is planning to encrypt this private-key information with a single symmetric-encryption key, and he's aware of the dangers that causes for resilience: the symmetric key becomes a Single Point of Failure.

He can't get around that (yet) but he can use the structure of the Envelope to offer other ways to rebuild his private keys. He adds a metadata hint to each Envelope: the derivationPath and the seedDigest of the seed used to create the keys. He does this by turning the xprv object into a new envelope containing the additional information as assertions.

"xpub6CiXsHfXkeXW2GBijsfihd64i8nebEWgxTxEq7j2ntT3GpyGKrP4v6dnz7ZNiZufVavY6pPwLTvdiUWSFD7tbCMpb3dvkpUq…" [
    "xprv": "xprv9yjBTn8dvGyCon7Fdr8iLV9LA6xABmnqbF2e2jKREYv4Q2e7nK4pNJKK8qrLMJNKHrNTyHUatP7TepCeTHPWv64HQShKfy6e…" [
        "derivationPath": "m/44h/0h/0h"
        "seedDigest": "d5377c9d8a2d064dc8e83d6c3557c6b0"
    ]
]

graph LR
    1(("65fb1c39<br/>NODE"))
    2["45c35879<br/>#quot;xpub6CiXsHfX...#quot;"]
    3(["b7a9b344<br/>ASSERTION"])
    4["d737f2ff<br/>#quot;xprv#quot;"]
    5(("be8d2de5<br/>NODE"))
    6["6ae4c8df<br/>#quot;xprv9yjBTn8d...#quot;"]
    7(["5c9b6166<br/>ASSERTION"])
    8["21a4d070<br/>#quot;seedDigest#quot;"]
    9["9e15a0d7<br/>#quot;d5377c9d8a2d064dc8e83d6c3557c6b0#quot;"]
    10(["bd90d97d<br/>ASSERTION"])
    11["d1f0d28b<br/>#quot;derivationPath#quot;"]
    12["6af50b61<br/>#quot;m/44h/0h/0h#quot;"]
    1 -->|subj| 2
    1 --> 3
    3 -->|pred| 4
    3 -->|obj| 5
    5 -->|subj| 6
    5 --> 7
    7 -->|pred| 8
    7 -->|obj| 9
    5 --> 10
    10 -->|pred| 11
    10 -->|obj| 12
    style 1 stroke:red,stroke-width:3.0px
    style 2 stroke:#55f,stroke-width:3.0px
    style 3 stroke:red,stroke-width:3.0px
    style 4 stroke:#55f,stroke-width:3.0px
    style 5 stroke:red,stroke-width:3.0px
    style 6 stroke:#55f,stroke-width:3.0px
    style 7 stroke:red,stroke-width:3.0px
    style 8 stroke:#55f,stroke-width:3.0px
    style 9 stroke:#55f,stroke-width:3.0px
    style 10 stroke:red,stroke-width:3.0px
    style 11 stroke:#55f,stroke-width:3.0px
    style 12 stroke:#55f,stroke-width:3.0px
    linkStyle 0 stroke:red,stroke-width:2.0px
    linkStyle 1 stroke-width:2.0px
    linkStyle 2 stroke:green,stroke-width:2.0px
    linkStyle 3 stroke:#55f,stroke-width:2.0px
    linkStyle 4 stroke:red,stroke-width:2.0px
    linkStyle 5 stroke-width:2.0px
    linkStyle 6 stroke:green,stroke-width:2.0px
    linkStyle 7 stroke:#55f,stroke-width:2.0px
    linkStyle 8 stroke-width:2.0px
    linkStyle 9 stroke:green,stroke-width:2.0px
    linkStyle 10 stroke:#55f,stroke-width:2.0px
Loading

With that done, he encrypts the xprv key with his symmetric key.

"xpub6CiXsHfXkeXW2GBijsfihd64i8nebEWgxTxEq7j2ntT3GpyGKrP4v6dnz7ZNiZufVavY6pPwLTvdiUWSFD7tbCMpb3dvkpUq…" [
    "xprv": ENCRYPTED [
        "derivationPath": "m/44h/0h/0h"
        "seedDigest": "d5377c9d8a2d064dc8e83d6c3557c6b0"
    ]
]

graph LR
    1(("65fb1c39<br/>NODE"))
    2["45c35879<br/>#quot;xpub6CiXsHfX...#quot;"]
    3(["b7a9b344<br/>ASSERTION"])
    4["d737f2ff<br/>#quot;xprv#quot;"]
    5(("be8d2de5<br/>NODE"))
    6>"6ae4c8df<br/>ENCRYPTED"]
    7(["5c9b6166<br/>ASSERTION"])
    8["21a4d070<br/>#quot;seedDigest#quot;"]
    9["9e15a0d7<br/>#quot;d5377c9d8a2d064dc8e83d6c3557c6b0#quot;"]
    10(["bd90d97d<br/>ASSERTION"])
    11["d1f0d28b<br/>#quot;derivationPath#quot;"]
    12["6af50b61<br/>#quot;m/44h/0h/0h#quot;"]
    1 -->|subj| 2
    1 --> 3
    3 -->|pred| 4
    3 -->|obj| 5
    5 -->|subj| 6
    5 --> 7
    7 -->|pred| 8
    7 -->|obj| 9
    5 --> 10
    10 -->|pred| 11
    10 -->|obj| 12
    style 1 stroke:red,stroke-width:3.0px
    style 2 stroke:#55f,stroke-width:3.0px
    style 3 stroke:red,stroke-width:3.0px
    style 4 stroke:#55f,stroke-width:3.0px
    style 5 stroke:red,stroke-width:3.0px
    style 6 stroke:#55f,stroke-width:3.0px,stroke-dasharray:5.0 5.0
    style 7 stroke:red,stroke-width:3.0px
    style 8 stroke:#55f,stroke-width:3.0px
    style 9 stroke:#55f,stroke-width:3.0px
    style 10 stroke:red,stroke-width:3.0px
    style 11 stroke:#55f,stroke-width:3.0px
    style 12 stroke:#55f,stroke-width:3.0px
    linkStyle 0 stroke:red,stroke-width:2.0px
    linkStyle 1 stroke-width:2.0px
    linkStyle 2 stroke:green,stroke-width:2.0px
    linkStyle 3 stroke:#55f,stroke-width:2.0px
    linkStyle 4 stroke:red,stroke-width:2.0px
    linkStyle 5 stroke-width:2.0px
    linkStyle 6 stroke:green,stroke-width:2.0px
    linkStyle 7 stroke:#55f,stroke-width:2.0px
    linkStyle 8 stroke-width:2.0px
    linkStyle 9 stroke:green,stroke-width:2.0px
    linkStyle 10 stroke:#55f,stroke-width:2.0px
Loading

Now, Sam can rapidly look up his many xprvs through their xpubs while storing them securely. If he ever loses the symmetric key that he used to encrypt his Gordian Envelopes, he can regenerate the private keys from the separately stored seeds, based on the seedDigest and derivationPath information.

#2. Sam is Salty about Compliance (Non-Correlation)

Problem Solved: Sam needs to avoid potential correlation of his data through hashes when selective disclosure is required.

Sam foresees a near-future where compliance regulations will require him to prove ownership of his private key. This will likely require selective disclosure. Sam is worried about the possibility of correlation for the additional data he's stored in his Gordian Envelope, even when it's elided.

The problem is that standard word like "derivationPath" or "seedDigest" or "m/44h/0h/0h" might be guessable by brute-forcing against the hash of the data. Fortunately, the problem is solvable by adding salt to those three elements. This adds a large random number as an assertion for each standard words. They can no longer be guessed. Even if their hashes need to be revealed as part of a compliance disclosure, the contents will remain secret.

"xpub6CiXsHfXkeXW2GBijsfihd64i8nebEWgxTxEq7j2ntT3GpyGKrP4v6dnz7ZNiZufVavY6pPwLTvdiUWSFD7tbCMpb3dvkpUq…" [
    "xprv": "xprv9yjBTn8dvGyCon7Fdr8iLV9LA6xABmnqbF2e2jKREYv4Q2e7nK4pNJKK8qrLMJNKHrNTyHUatP7TepCeTHPWv64HQShKfy6e…" [
        "derivationPath" [
            salt: Salt
        ]
        : "m/44h/0h/0h" [
            salt: Salt
        ]
        "seedDigest" [
            salt: Salt
        ]
        : "d5377c9d8a2d064dc8e83d6c3557c6b0"
    ]
]

graph LR
    1(("2b7312ce<br/>NODE"))
    2["45c35879<br/>#quot;xpub6CiXsHfX...#quot;"]
    3(["5884a988<br/>ASSERTION"])
    4["d737f2ff<br/>#quot;xprv#quot;"]
    5(("fe2e4ec6<br/>NODE"))
    6["6ae4c8df<br/>#quot;xprv9yjBTn8d...#quot;"]
    7(["a34707aa<br/>ASSERTION"])
    8(("ff559caa<br/>NODE"))
    9["21a4d070<br/>#quot;seedDigest#quot;"]
    10(["70f594d4<br/>ASSERTION"])
    11[/"3fb4814d<br/>salt"/]
    12["2522a29a<br/>Salt"]
    13["9e15a0d7<br/>#quot;d5377c9d8a2d064dc8e83d6c3557c6b0#quot;"]
    14(["d98de851<br/>ASSERTION"])
    15(("5471898d<br/>NODE"))
    16["d1f0d28b<br/>#quot;derivationPath#quot;"]
    17(["d512cd55<br/>ASSERTION"])
    18[/"3fb4814d<br/>salt"/]
    19["bcb4ddbc<br/>Salt"]
    20(("2845b3f3<br/>NODE"))
    21["6af50b61<br/>#quot;m/44h/0h/0h#quot;"]
    22(["b70d2f75<br/>ASSERTION"])
    23[/"3fb4814d<br/>salt"/]
    24["12e3ebf5<br/>Salt"]
    1 -->|subj| 2
    1 --> 3
    3 -->|pred| 4
    3 -->|obj| 5
    5 -->|subj| 6
    5 --> 7
    7 -->|pred| 8
    8 -->|subj| 9
    8 --> 10
    10 -->|pred| 11
    10 -->|obj| 12
    7 -->|obj| 13
    5 --> 14
    14 -->|pred| 15
    15 -->|subj| 16
    15 --> 17
    17 -->|pred| 18
    17 -->|obj| 19
    14 -->|obj| 20
    20 -->|subj| 21
    20 --> 22
    22 -->|pred| 23
    22 -->|obj| 24
    style 1 stroke:red,stroke-width:3.0px
    style 2 stroke:#55f,stroke-width:3.0px
    style 3 stroke:red,stroke-width:3.0px
    style 4 stroke:#55f,stroke-width:3.0px
    style 5 stroke:red,stroke-width:3.0px
    style 6 stroke:#55f,stroke-width:3.0px
    style 7 stroke:red,stroke-width:3.0px
    style 8 stroke:red,stroke-width:3.0px
    style 9 stroke:#55f,stroke-width:3.0px
    style 10 stroke:red,stroke-width:3.0px
    style 11 stroke:#55f,stroke-width:3.0px
    style 12 stroke:#55f,stroke-width:3.0px
    style 13 stroke:#55f,stroke-width:3.0px
    style 14 stroke:red,stroke-width:3.0px
    style 15 stroke:red,stroke-width:3.0px
    style 16 stroke:#55f,stroke-width:3.0px
    style 17 stroke:red,stroke-width:3.0px
    style 18 stroke:#55f,stroke-width:3.0px
    style 19 stroke:#55f,stroke-width:3.0px
    style 20 stroke:red,stroke-width:3.0px
    style 21 stroke:#55f,stroke-width:3.0px
    style 22 stroke:red,stroke-width:3.0px
    style 23 stroke:#55f,stroke-width:3.0px
    style 24 stroke:#55f,stroke-width:3.0px
    linkStyle 0 stroke:red,stroke-width:2.0px
    linkStyle 1 stroke-width:2.0px
    linkStyle 2 stroke:green,stroke-width:2.0px
    linkStyle 3 stroke:#55f,stroke-width:2.0px
    linkStyle 4 stroke:red,stroke-width:2.0px
    linkStyle 5 stroke-width:2.0px
    linkStyle 6 stroke:green,stroke-width:2.0px
    linkStyle 7 stroke:red,stroke-width:2.0px
    linkStyle 8 stroke-width:2.0px
    linkStyle 9 stroke:green,stroke-width:2.0px
    linkStyle 10 stroke:#55f,stroke-width:2.0px
    linkStyle 11 stroke:#55f,stroke-width:2.0px
    linkStyle 12 stroke-width:2.0px
    linkStyle 13 stroke:green,stroke-width:2.0px
    linkStyle 14 stroke:red,stroke-width:2.0px
    linkStyle 15 stroke-width:2.0px
    linkStyle 16 stroke:green,stroke-width:2.0px
    linkStyle 17 stroke:#55f,stroke-width:2.0px
    linkStyle 18 stroke:#55f,stroke-width:2.0px
    linkStyle 19 stroke:red,stroke-width:2.0px
    linkStyle 20 stroke-width:2.0px
    linkStyle 21 stroke:green,stroke-width:2.0px
    linkStyle 22 stroke:#55f,stroke-width:2.0px
Loading

#3. Sam Gets Paranoid about Privacy (Wrapped Encryption)

Problem Solved: Sam wants to add additional security and privacy, even if there is a cost.

SmartCustody is a constant battle between resilience and security. A few years later, Sam is rolling in the cryptocurrency earnings and decides that maybe he doesn't want his key derivation information sitting in plain sight. So, he adjusts all of his envelopes to allow the encryption of everything.

This requires "wrapping" the xprv information from the previous envelope, which means encapsulating it, and storing it as the subject of a new envelope. Encryption is an assertion, which means that it applies only to a subject. Previously that subject was just the xprv, but now it's the xprv and its subsidiary information.

(In the process of this adjusment, Sam also removes the salts he previously added, since eliding of the additional data is no longer an issue, and it makes the example clearer.)

Here's what the Gordian Envelope looked like originally:

"xpub6CiXsHfXkeXW2GBijsfihd64i8nebEWgxTxEq7j2ntT3GpyGKrP4v6dnz7ZNiZufVavY6pPwLTvdiUWSFD7tbCMpb3dvkpUq…" [
    "xprv": "xprv9yjBTn8dvGyCon7Fdr8iLV9LA6xABmnqbF2e2jKREYv4Q2e7nK4pNJKK8qrLMJNKHrNTyHUatP7TepCeTHPWv64HQShKfy6e…" [
        "derivationPath": "m/44h/0h/0h"
        "seedDigest": "d5377c9d8a2d064dc8e83d6c3557c6b0"
    ]
]

Here it is with the xprv information wrapped:

"xpub6CiXsHfXkeXW2GBijsfihd64i8nebEWgxTxEq7j2ntT3GpyGKrP4v6dnz7ZNiZufVavY6pPwLTvdiUWSFD7tbCMpb3dvkpUq…" [
    "xprv": {
        "xprv9yjBTn8dvGyCon7Fdr8iLV9LA6xABmnqbF2e2jKREYv4Q2e7nK4pNJKK8qrLMJNKHrNTyHUatP7TepCeTHPWv64HQShKfy6e…" [
            "derivationPath": "m/44h/0h/0h"
            "seedDigest": "d5377c9d8a2d064dc8e83d6c3557c6b0"
        ]
    }
]

graph LR
    1(("9cb57a98<br/>NODE"))
    2["45c35879<br/>#quot;xpub6CiXsHfX...#quot;"]
    3(["228f0998<br/>ASSERTION"])
    4["d737f2ff<br/>#quot;xprv#quot;"]
    5[/"5442e086<br/>WRAPPED"\]
    6(("be8d2de5<br/>NODE"))
    7["6ae4c8df<br/>#quot;xprv9yjBTn8d...#quot;"]
    8(["5c9b6166<br/>ASSERTION"])
    9["21a4d070<br/>#quot;seedDigest#quot;"]
    10["9e15a0d7<br/>#quot;d5377c9d8a2d064dc8e83d6c3557c6b0#quot;"]
    11(["bd90d97d<br/>ASSERTION"])
    12["d1f0d28b<br/>#quot;derivationPath#quot;"]
    13["6af50b61<br/>#quot;m/44h/0h/0h#quot;"]
    1 -->|subj| 2
    1 --> 3
    3 -->|pred| 4
    3 -->|obj| 5
    5 -->|subj| 6
    6 -->|subj| 7
    6 --> 8
    8 -->|pred| 9
    8 -->|obj| 10
    6 --> 11
    11 -->|pred| 12
    11 -->|obj| 13
    style 1 stroke:red,stroke-width:3.0px
    style 2 stroke:#55f,stroke-width:3.0px
    style 3 stroke:red,stroke-width:3.0px
    style 4 stroke:#55f,stroke-width:3.0px
    style 5 stroke:red,stroke-width:3.0px
    style 6 stroke:red,stroke-width:3.0px
    style 7 stroke:#55f,stroke-width:3.0px
    style 8 stroke:red,stroke-width:3.0px
    style 9 stroke:#55f,stroke-width:3.0px
    style 10 stroke:#55f,stroke-width:3.0px
    style 11 stroke:red,stroke-width:3.0px
    style 12 stroke:#55f,stroke-width:3.0px
    style 13 stroke:#55f,stroke-width:3.0px
    linkStyle 0 stroke:red,stroke-width:2.0px
    linkStyle 1 stroke-width:2.0px
    linkStyle 2 stroke:green,stroke-width:2.0px
    linkStyle 3 stroke:#55f,stroke-width:2.0px
    linkStyle 4 stroke:red,stroke-width:2.0px
    linkStyle 5 stroke:red,stroke-width:2.0px
    linkStyle 6 stroke-width:2.0px
    linkStyle 7 stroke:green,stroke-width:2.0px
    linkStyle 8 stroke:#55f,stroke-width:2.0px
    linkStyle 9 stroke-width:2.0px
    linkStyle 10 stroke:green,stroke-width:2.0px
    linkStyle 11 stroke:#55f,stroke-width:2.0px
Loading

Now, when Sam encrypts his data, he will encrypt everything within the envelope, not just the xprv itself.

"xpub6CiXsHfXkeXW2GBijsfihd64i8nebEWgxTxEq7j2ntT3GpyGKrP4v6dnz7ZNiZufVavY6pPwLTvdiUWSFD7tbCMpb3dvkpUq…" [
    "xprv": ENCRYPTED
]

graph LR
    1(("9cb57a98<br/>NODE"))
    2["45c35879<br/>#quot;xpub6CiXsHfX.#quot;"]
    3(["228f0998<br/>ASSERTION"])
    4["d737f2ff<br/>#quot;xprv#quot;"]
    5>"5442e086<br/>ENCRYPTED"]
    1 -->|subj| 2
    1 --> 3
    3 -->|pred| 4
    3 -->|obj| 5
    style 1 stroke:red,stroke-width:3.0px
    style 2 stroke:#55f,stroke-width:3.0px
    style 3 stroke:red,stroke-width:3.0px
    style 4 stroke:#55f,stroke-width:3.0px
    style 5 stroke:#55f,stroke-width:3.0px,stroke-dasharray:5.0 5.0
    linkStyle 0 stroke:red,stroke-width:2.0px
    linkStyle 1 stroke-width:2.0px
    linkStyle 2 stroke:green,stroke-width:2.0px
    linkStyle 3 stroke:#55f,stroke-width:2.0px
Loading

Of course, if Sam loses the symmetric key used to encrypt his Gordian Envelope without any metadata backup, he's going to have a very bad day ...

Part Two: Raising Resilience of Restricted Results

The second set of progressive use cases continues Sam's story, but demonstrates how to improve resilience when metadata can't be used, using either SSKR shares or multi-permits.

#4. Sam Gets Rigorous about Resilience (SSKR Permit)

Problem Solved: Sam wants to improve the resilience of his secrets by allowing for the possibility that some keys might be lost.

Sam's private key envelopes should provide good resilience. Unless he gets paranoid about privacy, they each contain metadata hints on how to regenerate that key from its seed. Even if he loses the symmetric key to an envelope's permit, he has enough information to rebuild the content by other means.

Sam will not have the same luxury with the envelopes that contain his seeds, especially since they must adhere to a very high level of security since they're the ultimate source of all his keys. He needs a new methodology for resilience: he thus chooses to lock his seed envelopes with Shamir's Secret Sharing, using Blockchain Commons' SSKR library. This will shard the symmetric key used to lock the envelope allowing him to recover it from just some of the shares (2-out-of-3 with the setup that Sam choses).

Sam wants to store the following seed:

HEX: 3f706e65f830bac081faafbb93730d3b
DIGEST: 651e44509ca8c719d25169f7e5e67d328e15007e171e1df2968b4a806d74984f

ur:crypto-seed/oyadgdfhjojtihyadyrdrtlyzsperkmujkbtfrhetehdax

Sam puts the UR version of the seed in an envelope indexed by the seed digest:

"651e44509ca8c719d25169f7e5e67d328e15007e171e1df2968b4a806d74984f" [
    "seed": "ur:crypto-seed/oyadgdfhjojtihyadyrdrtlyzsperkmujkbtfrhetehdax"
]

graph LR
    1(("7bc1b9e3<br/>NODE"))
    2["07ca56a9<br/>#quot;651e4450...#quot;"]
    3(["d3a547a4<br/>ASSERTION"])
    4["1911a33f<br/>#quot;seed#quot;"]
    5["468bfd55<br/>#quot;ur:crypto-seed/oyadgdfhjojtihyadyrdrtlyzsperkmujkbtfrhetehdax#quot;"]
    1 -->|subj| 2
    1 --> 3
    3 -->|pred| 4
    3 -->|obj| 5
    style 1 stroke:red,stroke-width:3.0px
    style 2 stroke:#55f,stroke-width:3.0px
    style 3 stroke:red,stroke-width:3.0px
    style 4 stroke:#55f,stroke-width:3.0px
    style 5 stroke:#55f,stroke-width:3.0px
    linkStyle 0 stroke:red,stroke-width:2.0px
    linkStyle 1 stroke-width:2.0px
    linkStyle 2 stroke:green,stroke-width:2.0px
    linkStyle 3 stroke:#55f,stroke-width:2.0px
Loading

Sam then shards the envelope with SSKR. This is a four-part process:

  1. Wrap the envelope.
  2. Encrypt the envelope.
  3. Shard the encryption key into multiple shares.
  4. Attach each share to a separate version of the encrypted data as an assertion.

Here is what Sam's wrapped envelope looks like:

{
    "651e44509ca8c719d25169f7e5e67d328e15007e171e1df2968b4a806d74984f" [
        "seed": "ur:crypto-seed/oyadgdfhjojtihyadyrdrtlyzsperkmujkbtfrhetehdax"
    ]
}

graph LR
    1[/"20a4182d<br/>WRAPPED"\]
    2(("7bc1b9e3<br/>NODE"))
    3["07ca56a9<br/>#quot;651e4450...#quot;"]
    4(["d3a547a4<br/>ASSERTION"])
    5["1911a33f<br/>#quot;seed#quot;"]
    6["468bfd55<br/>#quot;ur:crypto-seed/oyadgdfhjojtihyadyrdrtlyzsperkmujkbtfrhetehdax#quot;"]
    1 -->|subj| 2
    2 -->|subj| 3
    2 --> 4
    4 -->|pred| 5
    4 -->|obj| 6
    style 1 stroke:red,stroke-width:3.0px
    style 2 stroke:red,stroke-width:3.0px
    style 3 stroke:#55f,stroke-width:3.0px
    style 4 stroke:red,stroke-width:3.0px
    style 5 stroke:#55f,stroke-width:3.0px
    style 6 stroke:#55f,stroke-width:3.0px
    linkStyle 0 stroke:red,stroke-width:2.0px
    linkStyle 1 stroke:red,stroke-width:2.0px
    linkStyle 2 stroke-width:2.0px
    linkStyle 3 stroke:green,stroke-width:2.0px
    linkStyle 4 stroke:#55f,stroke-width:2.0px
Loading

Here is the encrypted envelope:

ENCRYPTED

graph LR
    1>"20a4182d<br/>ENCRYPTED"]
    style 1 stroke:#55f,stroke-width:3.0px,stroke-dasharray:5.0 5.0
Loading

Here is the envelope once it's been matched up with an SSKR share:

ENCRYPTED [
    sskrShare: SSKRShare
]

There are actually three versions of this envelope, each containing a share of the encryption key. Because he did a 2-of-3 sharding, Sam can recover the encrypted contents with any two different versions of the envelope.

graph LR
    1(("b9fa9fa0<br/>NODE"))
    2>"20a4182d<br/>ENCRYPTED"]
    3(["00348c8e<br/>ASSERTION"])
    4[/"79844d6b<br/>sskrShare"/]
    5["d9088803<br/>SSKRShare"]
    1 -->|subj| 2
    1 --> 3
    3 -->|pred| 4
    3 -->|obj| 5
    style 1 stroke:red,stroke-width:3.0px
    style 2 stroke:#55f,stroke-width:3.0px,stroke-dasharray:5.0 5.0
    style 3 stroke:red,stroke-width:3.0px
    style 4 stroke:#55f,stroke-width:3.0px
    style 5 stroke:#55f,stroke-width:3.0px
    linkStyle 0 stroke:red,stroke-width:2.0px
    linkStyle 1 stroke-width:2.0px
    linkStyle 2 stroke:green,stroke-width:2.0px
    linkStyle 3 stroke:#55f,stroke-width:2.0px
Loading 
graph LR
    1(("0b6f5b7f<br/>NODE"))
    2>"20a4182d<br/>ENCRYPTED"]
    3(["3359af08<br/>ASSERTION"])
    4[/"79844d6b<br/>sskrShare"/]
    5["424dadba<br/>SSKRShare"]
    1 -->|subj| 2
    1 --> 3
    3 -->|pred| 4
    3 -->|obj| 5
    style 1 stroke:red,stroke-width:3.0px
    style 2 stroke:#55f,stroke-width:3.0px,stroke-dasharray:5.0 5.0
    style 3 stroke:red,stroke-width:3.0px
    style 4 stroke:#55f,stroke-width:3.0px
    style 5 stroke:#55f,stroke-width:3.0px
    linkStyle 0 stroke:red,stroke-width:2.0px
    linkStyle 1 stroke-width:2.0px
    linkStyle 2 stroke:green,stroke-width:2.0px
    linkStyle 3 stroke:#55f,stroke-width:2.0px
Loading 
graph LR
    1(("ae4d7329<br/>NODE"))
    2>"20a4182d<br/>ENCRYPTED"]
    3(["f9b5470c<br/>ASSERTION"])
    4[/"79844d6b<br/>sskrShare"/]
    5["bfbb701b<br/>SSKRShare"]
    1 -->|subj| 2
    1 --> 3
    3 -->|pred| 4
    3 -->|obj| 5
    style 1 stroke:red,stroke-width:3.0px
    style 2 stroke:#55f,stroke-width:3.0px,stroke-dasharray:5.0 5.0
    style 3 stroke:red,stroke-width:3.0px
    style 4 stroke:#55f,stroke-width:3.0px
    style 5 stroke:#55f,stroke-width:3.0px
    linkStyle 0 stroke:red,stroke-width:2.0px
    linkStyle 1 stroke-width:2.0px
    linkStyle 2 stroke:green,stroke-width:2.0px
    linkStyle 3 stroke:#55f,stroke-width:2.0px
Loading

Note that all three Gordian Envelopes have the exact same encrypted data, whose hash matches the wrapped information that Sam is storing, but that they each contains a different SSKRshare, as shown by the varying hashes.

Sam stores one copy of his share at home, one at his bank, and one at work. If he ever loses this seed, he can restore it by bringing any two of these envelope shares together.

See 02-SSKR-Example in the Envelope-CLI docs for an example of how to produce SSKR shared Envelopes with the CLI.

#5. Sam Promotes a Partner (Multi-permit)

Problem Solved: Sam wants to give someone else access to his digital assets, without affecting his current resilient setup.

Sam takes on a partner: his super wife, Sophia. He now wants to make it easy for her to recover his funds if something happens to him. To do so, he rerolls his envelope with a second permit. It can still be opened with SSKR shares (which must be regenerated as part of the process), but now the envelope is also locked with Sophia's public key, which allows her to open it with her private key.

The three sharded Envelopes are created in the same way as when Sam just locked them with his SSKR shares, but now when the encryption occurs, a second assertion is added to each envelope, hasRecipient:

ENCRYPTED [
    hasRecipient: SealedMessage
    sskrShare: SSKRShare
]

As usual, the Mermaid output shows a bit more detail. Not only is the sskrShare different for each envelope, but so is each sealedMessage.

graph LR
    1(("9ae72792<br/>NODE"))
    2>"20a4182d<br/>ENCRYPTED"]
    3(["74956b04<br/>ASSERTION"])
    4[/"79844d6b<br/>sskrShare"/]
    5["01cf35d4<br/>SSKRShare"]
    6(["eda00f85<br/>ASSERTION"])
    7[/"f4af70d6<br/>hasRecipient"/]
    8["7ef934dc<br/>SealedMessage"]
    1 -->|subj| 2
    1 --> 3
    3 -->|pred| 4
    3 -->|obj| 5
    1 --> 6
    6 -->|pred| 7
    6 -->|obj| 8
    style 1 stroke:red,stroke-width:3.0px
    style 2 stroke:#55f,stroke-width:3.0px,stroke-dasharray:5.0 5.0
    style 3 stroke:red,stroke-width:3.0px
    style 4 stroke:#55f,stroke-width:3.0px
    style 5 stroke:#55f,stroke-width:3.0px
    style 6 stroke:red,stroke-width:3.0px
    style 7 stroke:#55f,stroke-width:3.0px
    style 8 stroke:#55f,stroke-width:3.0px
    linkStyle 0 stroke:red,stroke-width:2.0px
    linkStyle 1 stroke-width:2.0px
    linkStyle 2 stroke:green,stroke-width:2.0px
    linkStyle 3 stroke:#55f,stroke-width:2.0px
    linkStyle 4 stroke-width:2.0px
    linkStyle 5 stroke:green,stroke-width:2.0px
    linkStyle 6 stroke:#55f,stroke-width:2.0px
Loading 
graph LR
    1(("42a90638<br/>NODE"))
    2>"20a4182d<br/>ENCRYPTED"]
    3(["10736e0b<br/>ASSERTION"])
    4[/"79844d6b<br/>sskrShare"/]
    5["1f531682<br/>SSKRShare"]
    6(["fe3c2d3d<br/>ASSERTION"])
    7[/"f4af70d6<br/>hasRecipient"/]
    8["1220c907<br/>SealedMessage"]
    1 -->|subj| 2
    1 --> 3
    3 -->|pred| 4
    3 -->|obj| 5
    1 --> 6
    6 -->|pred| 7
    6 -->|obj| 8
    style 1 stroke:red,stroke-width:3.0px
    style 2 stroke:#55f,stroke-width:3.0px,stroke-dasharray:5.0 5.0
    style 3 stroke:red,stroke-width:3.0px
    style 4 stroke:#55f,stroke-width:3.0px
    style 5 stroke:#55f,stroke-width:3.0px
    style 6 stroke:red,stroke-width:3.0px
    style 7 stroke:#55f,stroke-width:3.0px
    style 8 stroke:#55f,stroke-width:3.0px
    linkStyle 0 stroke:red,stroke-width:2.0px
    linkStyle 1 stroke-width:2.0px
    linkStyle 2 stroke:green,stroke-width:2.0px
    linkStyle 3 stroke:#55f,stroke-width:2.0px
    linkStyle 4 stroke-width:2.0px
    linkStyle 5 stroke:green,stroke-width:2.0px
    linkStyle 6 stroke:#55f,stroke-width:2.0px
Loading 
graph LR
    1(("fa8b5c19<br/>NODE"))
    2>"20a4182d<br/>ENCRYPTED"]
    3(["06c93a5b<br/>ASSERTION"])
    4[/"f4af70d6<br/>hasRecipient"/]
    5["1de947d5<br/>SealedMessage"]
    6(["726831c2<br/>ASSERTION"])
    7[/"79844d6b<br/>sskrShare"/]
    8["5d8f5d3a<br/>SSKRShare"]
    1 -->|subj| 2
    1 --> 3
    3 -->|pred| 4
    3 -->|obj| 5
    1 --> 6
    6 -->|pred| 7
    6 -->|obj| 8
    style 1 stroke:red,stroke-width:3.0px
    style 2 stroke:#55f,stroke-width:3.0px,stroke-dasharray:5.0 5.0
    style 3 stroke:red,stroke-width:3.0px
    style 4 stroke:#55f,stroke-width:3.0px
    style 5 stroke:#55f,stroke-width:3.0px
    style 6 stroke:red,stroke-width:3.0px
    style 7 stroke:#55f,stroke-width:3.0px
    style 8 stroke:#55f,stroke-width:3.0px
    linkStyle 0 stroke:red,stroke-width:2.0px
    linkStyle 1 stroke-width:2.0px
    linkStyle 2 stroke:green,stroke-width:2.0px
    linkStyle 3 stroke:#55f,stroke-width:2.0px
    linkStyle 4 stroke-width:2.0px
    linkStyle 5 stroke:green,stroke-width:2.0px
    linkStyle 6 stroke:#55f,stroke-width:2.0px
Loading

That's because the creation of the SealedMessage is a multi-part process. The major steps are:

  1. Randomly generate a nonce.
  2. Encrypt the symmetric key used to encrypt the Envelope using the recipient's public key and the nonce.
  3. Store the encrypted key and the nonce in a crypto-message, stored in sealedMessage.

It's the usage of a nonce with each encryption that causes the SealedMessage for each share of the Envelope to vary.

Now, Sam can feel increasingly comfortable about the resilience of his envelope, knowing that not only can he recover it by putting together SSKR shares, but that his wife can recover it as well, using her private key (which presumably she protects from both compromise and failure using her own #SmartCustody methodology).

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