jiebi/CodeConvo huggingface dataset:
6. An entity in the RATS architecture includes at least one of the roles <del> defined in this document.  As a result, the entity can participate as a constituent of the RATS architecture.  Additionally, an entity can aggregate more than one role into itself.  These collapsed roles combine the duties of multiple roles.  In these cases, interaction between these roles do not necessarily use the Internet Protocol. They can be using a loopback device or other IP-based communication between separate environments, but they do not have to.  Alternative channels to convey conceptual messages include function calls, sockets, GPIO interfaces, local busses, or hypervisor calls.  This type of conveyance is typically found in Composite Devices.  Most importantly, these conveyance methods are out-of-scope of RATS, but they are presumed to exist in order to convey conceptual messages appropriately between roles. </del> <ins> defined in this document.  An entity can aggregate more than one role into itself.  These collapsed roles combine the duties of multiple roles. In these cases, interaction between these roles do not necessarily use the Internet Protocol.  They can be using a loopback device or other IP-based communication between separate environments, but they do not have to.  Alternative channels to convey conceptual messages include function calls, sockets, GPIO interfaces, local busses, or hypervisor calls.  This type of conveyance is typically found in Composite Devices.  Most importantly, these conveyance methods are out-of-scope of RATS, but they are presumed to exist in order to convey conceptual messages appropriately between roles. </ins> For example, an entity that both connects to a wide-area network and to a system bus is taking on both the Attester and Verifier roles.
An Attester creates Evidence that is conveyed to a Verifier. The Verifier uses the Evidence, and any Endorsements from Endorsers, <del> by applying an Evidence Appraisal Policy to assess the </del> <ins> by applying an Appraisal Policy for Evidence to assess the </ins> trustworthiness of the Attester, and generates Attestation Results for use by Relying Parties.  The Appraisal Policy for Evidence might be obtained from an Endorser along with the Endorsements, or might be
by applying an Appraisal Policy for Evidence to assess the trustworthiness of the Attester, and generates Attestation Results for use by Relying Parties.  The Appraisal Policy for Evidence might <del> be obtained from an Endorser along with the Endorsements, or might be obtained via some other mechanism such as being configured in the Verifier by an administrator. </del> <ins> be obtained from an Endorser along with the Endorsements, and/or might be obtained via some other mechanism such as being configured in the Verifier by the Verifier Owner. </ins> The Relying Party uses Attestation Results by applying its own Appraisal Policy to make application-specific decisions such as authorization decisions.  The Appraisal Policy for Attestation <del> Results might, for example, be configured in the Relying Party by an administrator. </del> <ins> Results is configured in the Relying Party by the Relying Party Owner, and/or is programmed into the Relying Party. </ins> 4.1.
An Attester creates Evidence that is conveyed to a Verifier. <del> The Verifier uses the Evidence, and any Endorsements from Endorsers, by applying an Appraisal Policy for Evidence to assess the trustworthiness of the Attester, and generates Attestation Results for use by Relying Parties.  The Appraisal Policy for Evidence might be obtained from an Endorser along with the Endorsements, and/or might be obtained via some other mechanism such as being configured in the Verifier by the Verifier Owner. </del> <ins> The Verifier uses the Evidence, any Reference Values from Reference Value Providers, and any Endorsements from Endorsers, by applying an Appraisal Policy for Evidence to assess the trustworthiness of the Attester, and generates Attestation Results for use by Relying Parties.  The Appraisal Policy for Evidence might be obtained from an Endorser along with the Endorsements, and/or might be obtained via some other mechanism such as being configured in the Verifier by the Verifier Owner. </ins> The Relying Party uses Attestation Results by applying its own appraisal policy to make application-specific decisions such as
It is also worth pointing out that the choice of model is generally up to the Relying Party.  The same device may need to create Evidence for different Relying Parties and/or different use cases.  For <del> instance, it would provide Evidence to a network infrastructure device to gain access to the network, and to a server holding confidential data to gain access to that data.  As such, both models may simultaneously be in use by the same device. </del> <ins> instance, it would use one model to provide Evidence to a network infrastructure device to gain access to the network, and the other model to provide Evidence to a server holding confidential data to gain access to that data.  As such, both models may simultaneously be in use by the same device. </ins> combination shows another example of a combination where Relying Party 1 uses the passport model, whereas Relying Party 2 uses an
As a system bus-connected entity, a Verifier consumes Evidence from other devices connected to the system bus that implement Attester roles.  As a wide-area network connected entity, it may implement an <del> Attester role.  The entity, as a system bus Verifier, may choose to fully isolate its role as a wide-area network Attester. </del> <ins> Attester role. </ins> In essence, an entity that combines more than one role creates and consumes the corresponding conceptual messages as defined in this
12.1. <del> Implementers need to pay close attention to the isolation and protection of the Attester and the factory processes for provisioning the Attestation key material.  If either of these are compromised, the remote attestation becomes worthless because the attacker can forge Evidence. </del> <ins> Implementers need to pay close attention to the protection of the Attester and the factory processes for provisioning the Attestation key material.  If either of these are compromised, the remote attestation becomes worthless because an attacker can forge Evidence or manipulate the Attesting Environment.  For example, a Target Environment should not be able to tamper with the Attesting Environment that measures it, by isolating the two environments from each other in some way. </ins> Remote attestation applies to use cases with a range of security requirements, so the protections discussed here range from low to
vouched for via Endorsements because no Evidence is generated about them are referred to as roots of trust. <del> The manufacturer of the Attester arranges for its Attesting Environment to be provisioned with key material.  The key material is typically in the form of an asymmetric key pair (e.g., an RSA or ECDSA private key and a manufacturer-signed IDevID certificate) secured in the Attester. The Verifier is provided with an appropriate trust anchor, or provided with a database of public keys (rather than certificates), or even carefully secured lists of symmetric keys.  The nature of how the Verifier manages to validate the signatures produced by the Attester is critical to the secure operation of an Attestation system, but is not the subject of standardization within this architecture. </del> <ins> The manufacturer having arranged for an Attesting Environment to be provisioned with key material with which to sign Evidence, the Verifier is then provided with some way of verifying the signature on the Evidence.  This may be in the form of an appropriate trust anchor, or the Verifier may be provided with a database of public keys (rather than certificates) or even carefully secured lists of symmetric keys. The nature of how the Verifier manages to validate the signatures produced by the Attester is critical to the secure operation of an Attestation system, but is not the subject of standardization within this architecture. </ins> A conveyance protocol that provides authentication and integrity protection can be used to convey unprotected Evidence, assuming the
boot, or immutable hardware/ROM. It is also important that the appraisal policy was itself obtained <del> securely.  As such, if appraisal policies for a Relying Party or for a Verifier can be configured via a network protocol, the ability to create Evidence about the integrity of the entity providing the appraisal policy needs to be considered. </del> <ins> securely.  If an attacker can configure appraisal policies for a Relying Party or for a Verifier, then integrity of the process is compromised. </ins> The security of conveyed information may be applied at different layers, whether by a conveyance protocol, or an information encoding
Claims about a root of trust typically are asserted by Endorsers. The device illustrated in layered includes (A) a BIOS stored in read- <del> only memory, (B) an updatable bootloader, and (C) an operating system kernel. </del> <ins> only memory, (B) an operating system kernel, and (C) an application or workload. </ins> Attesting Environment A, the read-only BIOS in this example, has to ensure the integrity of the bootloader (Target Environment B).  There
in read-only memory, (B) a bootloader, and (C) an operating system kernel. <del> The first Attesting Environment, the read-only BIOS in this example, has to ensure the integrity of the bootloader (the first Target </del> <ins> The first Attesting Environment, the ROM in this example, has to ensure the integrity of the bootloader (the first Target </ins> Environment).  There are potentially multiple kernels to boot, and the decision is up to the bootloader.  Only a bootloader with intact integrity will make an appropriate decision.  Therefore, the Claims
obtained via some other mechanism such as being configured in the Verifier by an administrator. <del> For example, for some claims the Verifier might check the values of claims in the Evidence against constraints specified in the Appraisal Policy for Evidence.  Such constraints might involve a comparison for equality against reference values, or a check for being in a range bounded by reference values, or membership in a set of reference values, or a check against values in other claims, or any other test. Such reference values might be specified as part of the Appraisal Policy for Evidence itself, or might be obtained from a separate source, such as an Endorsement, and then used by the Appraisal Policy for Evidence.  The actual data format and semantics of a known-good value are specific to claims and implementations.  There is no general purpose format for them or general means for comparison defined in this architecture document.  Similarly, for some claims the Verifier might check the values of claims in the Evidence for membership in a set, or against a range of values, or against known- bad values such as an expiration time.  These reference values may be conveyed to the Verifier as part of an Endorsement or as part of Appraisal Policy or both as these are the two input paths to the Verifier. </del> The Relying Party uses Attestation Results by applying its own Appraisal Policy to make application-specific decisions such as authorization decisions.  The Attestation Result Appraisal Policy
4.1. <ins> The Verifier, when appraising Evidence, or the Relying Party, when appraising Attestation Results, checks the values of some claims against constraints specified in its Appraisal Policy.  Such constraints might involve a comparison for equality against a reference value, or a check for being in a range bounded by reference values, or membership in a set of reference values, or a check against values in other claims, or any other test. Such reference values might be specified as part of the Appraisal Policy itself, or might be obtained from a separate source, such as an Endorsement, and then used by the Appraisal Policy. The actual data format and semantics of any reference values are specific to claims and implementations.  This architecture document does not define any general purpose format for them or general means for comparison. 4.2. </ins> An Attester consists of at least one Attesting Environment and at least one Target Environment.  In some implementations, the Attesting and Target Environments might be combined.  Other implementations
Universal Time, or might be defined relative to some other timestamp or timeticks counter. <del> We now walk through a number of hypothetical examples of how a solution might be built.  This list is not intended to be complete, but is just representative enough to highlight various timing considerations. </del> <ins> Using the table above, a number of hypothetical examples of how a solution might be built are illustrated below.  a solution might be built.  This list is not intended to be complete, but is just representative enough to highlight various timing considerations. </ins> 15.1.
15.3. The following example illustrates a hypothetical Background-Check <del> Model solution that uses timestamps and requires roughly synchronized clocks between the Attester, Verifier, and Relying Party. The time considerations in this example are equivalent to those discussed under Example 1 above. </del> <ins> Model solution that uses centrally generated identifiers for explicit time-keeping (referred to as "handle" in this example).  Handles can be qualifying data, such as nonces or signed timestamps.  In this example, centrally generated signed timestamps and - and synchronized clocks between all entities - are distributed in periodic intervals as handles.  If the Attester lacks a source of time based on an absolute timescale, a relative source of time, such as a tick counter can be used, alternatively.  In this example, evidence generation is not triggered at value generation, but at events at which the Attesting Environment becomes of changes to the Target Environment. In comparison with example 1, the time considerations in this example go into more detail with respect to the life-cycle of Claims and Evidence.  While the goal is to create up-to-date and recent Evidence as soon as possible, typically there is a latency between value generation and Attester awareness. At time(AA) the Attesting Environment is able to trigger an event (e.g. based on an Event-Condition-Action model) to create attestation Evidence that is as recent as possible.  In essence, at time(AA) the Attesting Environment is aware of new values that where generated at time(VG) and corresponding Claim values are collected immediately. Consecutively, Evidence based on relevant "old" Claims and the just collected "new" Claims is generated at time(EG).  In essence, the Claims used to generate the Evidence are generated at various time(VG) before time(AA). In order to create attestation Evidence at at time(AA), the Attester requires a fresh (i.e. not expired) centrally generated handle that has been distributed to all involved entities. In general, The duration a handle remains fresh depends on the content-type of the handle.  If it is a (relative or absolute) timestamp, clocks synchronized with a shared and trustworthy source of time are required.  If another value type is used as a handle, the reception time of the handle time(HD) provides an epoch (relative time of zero) for measuring the duration of validity (similar to a heart-beat timeout).  From the point of view of a Verifier, validity of Evidence is only given if the handle used in Evidence satisfies delta(time(HD),time(EG))distribution-interval. In this usage scenario, time(VG), time(AA), and time(EG) are tightly coupled.  Also, the absolute point in time at which a handle is received by all three entities is assumed to be close to identical. </ins> 15.4.
attempted against.  An empty redemption is returned when the limit has been hit: <ins> 5.4. A consequence of limiting the number of participants (Attesters or Issuers) in Privacy Pass deployments for meaningful privacy is that it forces concentrated centralization amongst those participants. CENTRALIZATION discusses several ways in which this might be mitigated.  For example, a multi-stakeholder governance model could be established to determine what participants are fit to operate as participants in a Privacy Pass deployment.  This is precisely the model used to control the Web's trust model. Alternatively, Privacy Pass deployments might mitigate this problem through implementation.  For example, rather than centralize the role of attestation in one or few entities, attestation could be a distributed function performed by a quorum of many parties, provided that neither Issuers nor Origins learn which attester implementations were chosen.  As a result, clients could have more opportunities to switch between attestation participants. </ins> 6. We present a number of security considerations that prevent malicious
properties include, though are not limited to: Capable of solving a CAPTCHA.  Clients that solve CAPTCHA <del> challenges can be attested to have this capability for the purposes of being ruled out as a bot or otherwise automated Client. </del> <ins> challenges can be attested to have this capability for the purpose of being ruled out as a bot or otherwise automated Client. </ins> Client state.  Clients can be associated with state and the attester can attest to this state.  Examples of state include the <del> number of issuance protocol invocations, the client's geographic </del> <ins> number of issuance protocol invocations, the Client's geographic </ins> region, and whether the client has a valid application-layer account. Trusted device.  Some Clients run on trusted hardware that are capable of producing device-level attestation statements. <del> Each of these attestation types have different security properties. </del> <ins> Each of these attestation types has different security properties. </ins> For example, attesting to having a valid account is different from attesting to running on trusted hardware.  In general, Attesters should accept a limited form of attestation formats.
on compliant devices, then the corresponding attestation format should be untrusted until the exploit is patched.  Addressing changes in attestation quality is therefore a deployment-specific task.  In <del> Split Attester and Issuer deployments, Issuers can choose to remove compromised Attesters from their trusted set until the compromise is patched, without needing to modify Origin allow-lists. </del> <ins> Split Attester and Issuer deployments (see deploy-split), Issuers can choose to remove compromised Attesters from their trusted set until the compromise is patched, without needing to modify Origin allow- lists. </ins> 3.2.2.
public metadata is metadata the client can see but cannot check for correctness.  As an example, the opaque public metadata might be a "fraud detection signal", computed on behalf of the Issuer, during <del> token issuance.  In normal circumstances, clients cannot determine if </del> <ins> token issuance.  In normal circumstances, Clients cannot determine if </ins> this value is correct or otherwise a tracking vector. <del> Private metadata is that which clients cannot observe as part of the </del> <ins> Private metadata is that which Clients cannot observe as part of the </ins> token issuance flow.  Such instantiations may be built on the Private Metadata Bit construction from Kreuter et al.  KLOR20 or the attribute-based VOPRF from Huang et al.  HIJK21.
Client anonymity.  Such techniques are closely linked to the type of key schedule that is used by the Issuer.  When an Issuer rotates their key, any Client that invokes the issuance protocol in this key <del> cycle will be part of a group of possible clients owning valid tokens </del> <ins> cycle will be part of a group of possible Clients owning valid tokens </ins> for this key.  To mechanize this attack strategy, an Issuer could introduce a key rotation policy that forces Clients into small key cycles, reducing the size of the anonymity set for these Clients.
partition, the Client limits the number of different Issuers used to a small number to maintain the privacy properties the Client requires.  As long as each redemption partition maintains a strong <del> privacy boundary with each other, the verifier will only be able to learn a number of bits of information up to the limits within that "redemption partition". </del> <ins> privacy boundary with the others, the number of bits of information the verifier can learn is bounded by the number of "redemption partitions". </ins> To support this strategy, the client keeps track of a "partition" which contains the set of Issuers that redemptions have been
6. <del> We present a number of security considerations that prevent malicious Clients from abusing the protocol. 6.1. </del> <ins> Beyond the aforementioned security gaols for the Issuance protocol (issuance-protocol), it is important for Privacy Pass deployments to mitigate the risk of abuse by malicious Clients. </ins> When a Client holds tokens for an Issuer, it is possible for any verifier to cause that client to redeem tokens for that Issuer.  This can lead to an attack where a malicious verifier can force a Client to spend all of their tokens from a given Issuer.  To prevent this from happening, tokens can be scoped to single Origins such that they <del> can only be redeemed within for a single Origin. </del> <ins> can only be redeemed for a single Origin. </ins> If tokens are cross-Origin, Clients should use alternate methods to prevent many tokens from being redeemed at once.  For example, if the
directly communicating with an Issuer.  Depending on the attestation, Attesters can store state about a Client, such as the number of overall tokens issued thus far.  As an example of an issuance <del> protocol, in the original Privacy Pass protocol PPSRV, tokens were </del> <ins> protocol, in the original Privacy Pass protocol PPEXT, tokens were </ins> only issued to Clients that solved CAPTCHAs.  In this context, the Attester attested that some client solved a CAPTCHA and the resulting token produced by the Issuer was proof of this fact.
valid token available, it presents the token to the origin (redemption). <ins> Unlike many authentication schemes in which a client will present the same credentials across multiple requests, tokens used with the "PrivateToken" scheme are single-use credentials, and are not reused. Spending the same token value more than once allows the origin to link multiple transactions to the same client.  In deployment scenarios where origins send token challenges to request tokens, origins ought to expect at most one request containing a token from the client in reaction to a particular challenge. </ins> 2.1. Origins send a token challenge to clients in an "WWW-Authenticate"
The Privacy Pass protocol provides a privacy-preserving authorization mechanism.  In essence, the protocol allows clients to provide cryptographic tokens that prove nothing other than that they have <del> been created by a given server in the past I-D.ietf-privacypass- architecture. </del> <ins> been created by a given server in the past ARCHITECTURE. </ins> This document describes the issuance protocol for Privacy Pass.  It specifies two variants: one that is privately verifiable based on the oblivious pseudorandom function from OPRF, and one that is publicly verifiable based on the blind RSA signature scheme BLINDRSA. <del> This document DOES NOT cover the architectural framework required for running and maintaining the Privacy Pass protocol in the Internet setting.  In addition, it DOES NOT cover the choices that are necessary for ensuring that client privacy leaks do not occur.  Both of these considerations are covered in I-D.ietf-privacypass- architecture. </del> <ins> This document does not cover the Privacy Pass architecture, including choices that are necessary for ensuring that client privacy leaks. This information is covered in ARCHITECTURE. </ins> 2.