PAC Theorem: Privacy, Authenticity, Confidentiality KERI and Zero Trust Data Management https://hackmd.io/Qsrfj7Y-TIGISESvrxWGxw e ) i RERI 202104)23
PAC Theorem A conversation may be two of the three, private, authentic, and confidential to the same degree, but not all three at the same degree. Authentic 9 g % g Trade-offs required!
Definitions
Private:
The parties to a conversation are only known by the parties to that conversation. Authentic:
The origin and content of any statement by a party to a conversation is provable to any other party. Confidential:
All statements in a conversation are only known by the parties to that conversation. Privacy:
about control over the disclosure of who participated is in the conversation (non-content meta-data) Authenticity:
about proving who said what in the conversation (secure attribution) Confidentiality:
about control over the disclosure of what was said in the conversation (content data) Relatively weak legal protection for non-content (supoena) - Relatively strong legal protection for content (search warrant) https:/fwww.lawfareblog.com/relative-vs-absolute-approaches-contentmetadata-line https:/fwww.pogo.orgfanalysis/2019/06/the-history-and-future-of-mass-metadata-surveillance/ N g
Proving Authenticity
Non-repudiable Proof:
a statement's author cannot successfully dispute its authorship
Asymmetric key-pair digital signature Repudiable Proof:
a statement's author can successfully dispute its authorship
DH shared symmetric key-pair encryption (auth crypt)
Shared secret makes every verifier a potential forger
Non-Repudiable Authenticity : 2 Signed with Verified with l Zoe private key n public key Sue Non-repudiable authenticity is zero-trust
Non-Repudiable Authenticity :2 Signed with Verified with & Zoe private key n public key Sue Non-repudiable authenticity is zero-trust
Repudiable Authenticity 2 Encrypted with - Decrypted with & Zoe shared private key shared private key Sue Repudiable authenticity requires trust (is not zero-trust)
Non-Repudiable Authenticity Is Legally Binding. Repudiable Authenticity Is Not Legally Binding. z Encrypted with ' Decrypted with & Zoe shared private key shared private key Sue Non-Repudiable authenticity has recourse. Best fits current business and regulatory eco-systems.
Zero Knowledge Proof? Q Authentic ZKP: Is the information proven in a repudiable or non-repudiable manner? & Zoe kP Sue one party (the prover) can prove to another party (the verifier) that a given statement s true, without conveying any information apart from the fact that the statement is indeed true. ZKP (selective disclosure) Zoe proves an element of a bundle of information to Sue without disclosing any other element of the bundle (non-repudiable or repudiable but repudiability may not be protected from forgery) Other “non-ZKP” methods can perform a non-repudiable selective disclosure ZKPOK (selective disclosure) Z0e proves to Sue that a given statement i true without enabling Sue to prove to a third party that the statement is true and protecting Alice from Sue as a forger. (plausible deniability, repudiability with forgery protection)
Trade-offs Private: The parties to a conversation are only known by the parties to that conversation. Authentic: The origin and content of any statement by a party to a conversation is provable to any other party. Confidential: All statements in a conversation are only known by the parties to that conversation. Non-repudiation means any party to conversation can proof to any other party exactly what was said by whom. ‘This means that technologically there is no way to prevent disclosure by any party to some third party. ‘We can incentivize confidentiality by imposing a liability on the parties to the disclosure set before disclosure Enforcement of that liability will usually necessarily violate privacy but not confidentiality. Authentic Real world value often requires transitivity. Transitive value transfer will violate complete privacy. o & % & % &
Strong Privacy? Weak Weak
Strong Privacy
Definition: un-correlated interactions over unbounded time and space. Super aggregators and state actors have effectively unlimited storage and compute capacity. Eventually all disclosed data will be at least statistically correlatable.
Weak Privacy
Definition: un-correlated interactions over bounded time and space.
when the cost of correlation exceeds the value of correlation the data will be un-correlated.
Operating Regimes Regulation andjor = Legally Enforced Contracts S = Hide E £ or S & Bribe A3 H Hide g and Criminally Enforced Contracts ? z Bribe Tllegitimate Legitimate Economic
Economics of Correlator predictive value S B s 8 H 5 8 8 time data lifecycle past now future measured predicted
Economics of Correlator: Value Extraction predictive value ] 3 K] 8 s s s s © 2 £ extractable value 5 8 - 8 time data lifecycle past now future measured predicted
Economics of De-correlator g predictive value s 3 5 g | £ g £ $ ] S time data lifecycle past now future measured predicted
Economics of De-correlator: Value Extraction s predictive value 3 K 8 5 extractable value 5 3 AN s £ 5 g g E 3 time data lifecycle past now future measured predicted
Freedom balanced Freedom from ... Freedomto ... exploitation (commercial) extract value(commercial) intimidation (political) build relationships (social) censorship (political) build community (political) possibility of erasure = possibility of censorship anonymity = loss-of-value from attribution fairness = loss of privacy from attribution
Three Party Exploitation Model
First-Party = Discloser of data. Second-Party = Disclosee of data received from First Party (Discloser) Third-Party = Observer of data disclosed by First Party (Discloser) to Second Party (Disclosee). Second-Party (Disclosee) Exploitation it permsioned coneaton
no contractual restrictions on the use of disclosed data. cxplist permissoned coneaion
{5025 parmitod oy contct explicit unpermissioned correlation with other second parties or third parties. Third-Party (Observer) Exploitation implt permssioned condaton
P conrasualrosctons o s of coserod et explicit unpermissioned correlation via collusion with second parties.
Palius ss i ideion of socon pary conract
Contractually Governed Exchanges
Ricardian Contracts:
Chain-link Confidentiality o
s e
Consent, Waiver, Terms-of-use, Remuneration, etc. — 2 — oo = o003 = oo = S °3
Chain-Link Confidentiality A chain-link confidentiality regime contractually links the disclosure of information to obligations to protect that information as the information moves downstream. The system focuses on the relationships not only between the discloser of information and the initial recipient but also between the initial recipient and subsequent recipients. Through the use of contracts, this approach links recipients of information as in a chain, with each subsequent recipient bound by the same obligation to protect the information. These chain contracts contain at least three kinds of terms: 1) obligations and restrictions on the use of the disclosed information; 2) requirements to bind future recipients to the same obligations and restrictions; and 3) requirements to perpetuate the contractual chain. This approach creates a system for the permissible dissemination of information. It protects Disclosers by ensuring that the recipient’s obligation to safeguard information is extended to third parties.
Least Disclosure Principle of Least Disclosure AACDCs are designed to satisfy the principle of least disclosure. The system should disclose only the minimum amount of information about a given party needed to facilitate a transaction and no more. Partial Disclosure Compactness Chain-link Confidentiality Selective Disclosure Unbundling Bulk-issuance Mechanisms: Compact via SAID over content Blinded via SAID over content with embedded UUID (salty-nonce) Unbundled via Aggregate of bundle of blinded content Uncorrelatable via bulk issued blinded content
Contractual Exchange Discloser provides a non-repudiable Offer with verifiable metadata (sufficient partial disclosure) which includes any terms or restrictions on use. Disclosee verifies Offer against composed schema and metadata adherence to desired data. Disclosee provides non-repudiable Accept of terms that are contingent on compliant disclosure. Discloser provides non-repudiable Disclosure with sufficient compliant detail. Disclosee verifies Disclosure using decomposed schema and adherence of disclosed data to Offer. Disclosee may now engage in permissioned use and carries liability as a deterrent against unpermissioned use.
Latent Accountability Escrow KYC Contingent Enforcement and Recourse Bonding Bounties Example Use Cases
Background