Bulk Issuance Balancing security of perpetually verifiable issuances with correlation risk for privacy protection . ) @ KZaiz ESA CONF Samuel M. Smith PhD
) sam@kerisuitte.org KGIU https://kericonf.com https://keri.foundation FOUNDATION
Tradespace Threats Identity Theft Attention Theft Intimidation
Tradespace Mitigations Perpetual Identity Pepetually Verifiable Issuances Control over Context Disclosure, Presence, & Usage
. Using ACDCs Graph Fragment edgels) e, 398 PrOPertes | orex fnode) I~ 1 e properes [ J Veriex L Perpetually Verifiable Issuances L Each Fragment is Separably Authenticatable Delegable Attenuable Aggrable Revocable Transferable Authority High Fidelity Modeling of Real World Authority Structures
ACDC Confidentiality/Privacy Protections
Least Disclosure:
The system should disclose only the minimum amount of information about a given party
needed to facilitate a transaction, and no more Graduated Disclosure: progressive least disclosures that each enable further disclosure Contractually Protected Disclosure:
Uses graduated disclosure to minimize leakage prior to legally enforceable protection IPEX Protocol (issuance and presentation exchange) Blindable ACDC State Registries Bindable Blindable Delegated ACDC State Registries:
perpetually verifiable, dynamically revocable, delegable, transferable
Graduated Disclosure (circa 2020) Compact Disclosure (SAID) Partial Disclosure Nested Partial Disclosure Full Disclosure Selective Disclosure Metadata Disclosure (ACDC with some instantiation of nested partial and selective necessary to gain agreement) Bulk-issued Instance Disclosure (validator-to-validator cryptographic unlinkability) Combinations of the above
Contractually Protected Disclosure (circa 2020)
Uses graduated disclosure to minimize leakage prior to legally enforceable protection Chain-Link Confidential Disclosure: strings attached downstream of disclosure, ubiquitous counter-incentive to correlate Contingent Disclosure:
Conditions for additional disclosure on disclosee, Escrow disclosure, JIT-NTK disclosure,
and Latent Accountability Legal protection may include retroactive anti-assimilation terms that plug leaks in the graduated disclosure process Negotiated via IPEX Protocol (issuance and presentation exchange)
Blindable State for Bulk Issuance Protected Disclosure (circa 2023-2025) Blindable ACDC State Registries Bindable Blindable Delegated ACDC State Registries
perpetually verifiable, dynamically revocable, transferable, delegable entitlements
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ACDC 1 PR R i ST s T [S4D LD s D Rty e o] e | Regsty Incepton Exent rip) ) . PR A 4000 st sy s o s s | AGDC epsner |[vorson| T[540 w0 sverh ¥ Dstie e s — Sore s [ St s Rep B Ui Evr o) o o T vt ] [ v T e | PR R T plefme [ et oo versn | Tpe 54D [Regay s o | ot 510 1| i o crwn]| 5o | LT e [ s ] = 2| e o : ER 3] the | s 5 fromnn ol ‘,,2 Inferact Mo Change | Seal = — Sy —— H {2 bt [btre| s | o s s © = U 5 e ) b B P astsczc R T et [ ot ey S s oo S | e e e oy —wosom—] BB | 5 = ) s AT, 5| rome | ome | s | o[ e o
[ acoc Ve w o m s e [Versan | Tpe | SAD UL sser AD Ry Schemal Atite Edpe Ruke Rogty ncaption Event ) ) Regsty Binded Updsle Even oup) [ A ok ) P R T P R S @ woow s Veson| Ty | SWD WD umrAD SN D] Ve | Tye | SAD Regsy SN pro | Daotne s || || 810 | wp [ acocsan | s i . Binded State Registy (TEL) fssuer Key Event Log (KEL) | ACDC RegistrariObserver Transacton . SN Event KeySta EventSedls ACDC Stae Regtry o T oept | ot Transaction Event Log (TEL) ool o | et | SN Bt BLD 1| meract | NoChange | sea o v | . .| Binded Atnute Blocks (8ABs) _ 2 | iteract | NoChange | seal 1 | Upsate | .. ] 8UD [ WU | empty | ampty - 3| Rowte | crange | seal 2 [Upsate | .. ‘ BUD [ uu | AcDC | issued .4 | teract | NoChange | seal 3 | ptate | . - ‘ BUD [ UUD | ACDC | issued 5| Roste | Change | sea 4 Ve | . ‘ BUD [ UUID | AGDC | revoked 6| Roate | Change | Sea 5 | Uptate| .. — BLD | UUID | AGDC | revoked
( ACDC Registry Inception Event {rip) [ Registry Biinded Update Event (bup) Binded Allibule Block (BAB) Vs T[540 0D s SN] i | vrion e[ SA0. Rags |54 s |30 |8 |wio cocsun| s Blinded State Ragisty (TEL} Tesuar Koy Evart Log KEL} ACOC RegstatiOosooer | B A ‘Transaction Event Log (TEL) [l g s ]| Lo [ oo [ 2] erct [ NoGrange | Seal 1 upcate = 8D D | empty | emy | [ mm oo [ s |7 e om0 e mor s | [T e s ]| me om0 [0 e | [lmm owp [ ] el om0 w0 e ] (o oo | omoe | son | |5 wme . oo e o
Registrar and Observer [ Observer | ver Registrar |——" 2 st it wponns e Pov PN S ST W Y & e ) N é’&&‘ | registies ==} /;slsle*; oV ‘ Observer /:';://’ Pov regeres o &fié [ state =" PoV I TEL registres N = &‘9‘ e [ e | [ Regstar | o L s v | — ovents — registes bulk (" Obseer ST o py ‘&@ o dl) A Sl L L Sregies [%:5,& P
: . Usage Presentation Registry
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Identity Assurance and Reputation o ently dentiy Assurance b s / N registry. P \ 5 / S ey s N\ aldtor eypa |+ | tntter | Relatively weak binding reinforced by multiple bindings = reputation
IAPC ACDC An in-person session that binds identity assurance to cryptographic identity NIST IAL3 Compliant SEDI Account AID MITM protected challenge response of proof of control over AID Proofing Agent issues identity assurance proof-of-control ACDC to Account AID IAPCinclude core attributes + biometric Account AID is later presented to State to request bulk issuance of SEDI credentials This enables dynamic sizing of SEDI bulk issuance sets
ACDC Bulk Issuance with full cryptographic unlinkability validator to validator The UUIDs in each member of a bulk-issued set are derived using an HDKey algorithm whose path contains a shared secret salt, the member index, and the UUID index. Each member of a bulk-issued set has a unique AID with unique keys derived using an HDKey algorithm whose derivation contains a non-shared private salt, a shared secret salt, and the member index. When using independent registry bulk-issued ACDCs, the total number of registries for a given set of bulk-issued ACDCs typically equals the number of members in that set. Alternatively, a given Issuer could use one blinded state tel for multiple different ACDCs, thereby providing herd privacy across all issuances.
Sparse Merkle Tree Optimized Compact Sparse Merkle Tree (all operations O(logN))
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Bulk Issuance All the seals are anchored using a single seal, which is the Merkle root of a Sparse Merkle tree that references the transaction events for all the independent Registry TELs. In a Sparse Merkle tree, the seals are only stored in leaf nodes of the tree, not in intermediate nodes Sparse Merkle trees (SMTs) were originally developed for the Certificate Transparency (CT) network. Since then, various optimized versions of SMT have been developed Efficient inclusion proofs in an SMT enable a given Issuer to amalgamate all Registry transaction event seals for its bulk-issued ACDCs into a single SMT. This provides so-called herd privacy to the updates.
Bulk Issuance Continued To further strengthen herd privacy, when using blindable state Registries, the Issuer could randomly issue update events that do not change state, across all its registries, mixing updates over time and across each registry. This would ensure that enough updates are captured by each batch anchoring seal to guarantee a pre-specified level of herd privacy. A given seal in the KEL of the Issuer no longer provides a point of correlation to any other transaction event to any given registry. A given inclusion proof for one event from one Registry does not reveal inclusion for events in other Registries or correlate a given bulk-issued ACDC to any other bulk-issued ACDC using a different Registry. This amalgamation requires only one seal in the Issuer's KEL. Using an optimized SMT algorithm enables an Issuer to provide efficient inclusion proofs for an amalgamated SMT of all transaction update events across all Registries for all bulk-issued ACDCs to all Issuees.
More Bulk Issuance When using blindable state update events in these Registries, then the ACDC is not viewable by a 3rd party. Because the SMT provides herd privacy with respect to which Registries with their transaction event updates belong to which bulk-issued sets of ACDCS, a pair of malicious 2nd parties cannot compare inclusion proofs to determine if two ACDCs belong to the same bulk-issued set. Moreover, because each ACDC in a bulk-issued set gets its own Registry, the registry database does not provide a point of correlation between two different Registries that belong to the same bulk-issued set of ACDCs. Therefore, a given disclosure of a bulk-issued ACDC does not directly disclose any points of correlation between malicious 2nd parties.
ACDC Blinded Registry Example Registry Inception Registry Placeholder Update i TACOCCARCARISONMR. L ACOCCAACARISONAAES e PO "d" "ECONDL3kAJpCFYITReNDX2uGE-Gs6LhyKLO-0r3q0TC" " "EPNuyVHP2X]sZ9PSPXtHECCmzWEbKSFC-nhGKTbSoaYE" , u"s "GABNVZRIc3BLY3dvamtyVXex”, "rd: "ECOMII9KkA]PCFYITRenpIx2w66-GSGLhYKLO-0r3901Q" 147 "ECHIZEBELLASOESUOraMTSE BUSHEDKCAY ORI YT, e e, "pM: MECOWIIOKA]PCFYITRenpIx2w66-GsGLhyKLO-0r3q0IQ", NGt 20280704711 551109.000000400:00" e } "b": "ECVrTQWEP_2qVQuzayprRFXVx1-9ukLx_d6oDinlHUEI" ) ViiLabel Ve cescriaion . [ —————— Ty T [ FVTT o —————r-p—) = gy Tasacion ACOG SAD fd v, oo 4 Unblinded attribute block as attachment to disclosure of TEL Event aRYECUTTGHED_aaQuzyarAF 3 -. _dSoD G313 TT o 6Tz Py GHPLLTLhAUKUEIARPIARP Placeholder updates provide herd privacy wrt correlation to date time of actual state changes
ACDC Blinded Registry Example ... Registry Issued Update i PACDCCAACARISONRAE s 4 By 20CAdna - CHLSGLHG2LIGBSLTRAESNTON' e ECIIIKAJPCYI1Ren 268G KLO-0r3G010", PR ————— gt "2820-08-02112:00:20.000000100:00", 57 "EOtMOX_ 003Ukl ZSICHINALTZSYSH_Hr_c" Vit Labe Vet Descrption . [P —— R - B o ity | UUID oty nancs binang fcton random o HD gsnrted @ 50 ok s ot mcen | Tansnton AGDC SAI ild vauetop-evl ¢ 5 s ansactonstatovalu sting
ACDC Blinded Registry Example ... Registry Issued Update
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g "Bl 2DCAdna - CHLSGUHE2LIGBSLTRAZSNTEN'
gt "2020-08-03T12:00:20.000000100:00",
5 7EP3521500NTHTgANSuZVYdhNeos SaxgEns PbS TCARNY Virtual Label Value Description d EPj35ZjB0OWTKTgANSVZVYdANeo ] 3zxgENSAPbf CRAN. Dummied BLID (Blinding SAID) u TGP TSS OG0RYOEE wi\dasbcdkonanty2 UUID salty nonce blinding factor H generated w UL 2L LU0GKox_SOMGaT0-OudoGHOubaT26ucdtt Transaction ACDC SAID fild value, top-fovel o - Yrevoked Transaction sate value sring