Security

Vtslx AO: sensitive context handling

A public architecture and governance note for minimizing, routing, retaining, and auditing highly sensitive AI context.

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Sensitive context handling cover

Research summary

Highly sensitive project context cannot be protected by a single redaction pass at the edge. This note presents a control-plane model for classifying, minimizing, routing, retaining, using, and auditing AI context across its full lifecycle. Our objective is not to promise that any model understands secrets safely; it is to ensure that the system never needs to send, store, or expose more context than an authorized task requires.

1. Scope and design position

The system handles code, documents, credentials, customer records, tool output, retrieval results, and generated text that may carry different sensitivity levels. We use explicit classification and purpose binding rather than relying on a vague “private mode.” The default question is not whether a useful file can be included, but whether its minimum necessary representation is authorized for this task, route, model, tool, and retention period.

2. Context control plane

The control plane sits before model routing and alongside tool execution. It combines asset classification, purpose and tenant binding, minimization, approved-route selection, retention policy, and minimal audit evidence. The data plane then receives only the selected, authorized context.

调用方 / 业务系统入口:身份、分类、最小化上下文信封:目的、范围、级别、许可AO 网关:策略、路由、预算、审计模型执行受限工具 / MCP回包按不可信内容复检出口:输出检查、流式治理
图 1. 高度敏感上下文控制面。上下文信封携带目的、范围、级别与许可,而非复制原文;模型、工具、回包与出口分别处于不同信任边界。

敏感上下文策略探索器

选择数据级别与目标路径,查看公开策略语义;不展示生产地址、密钥、阈值或供应商配置。

高度敏感不携带密钥、完整身份资料或无关原件;先分类裁剪。
默认路由与保留默认隔离执行,对外出口需显式审批。 不缓存正文、不持久化正文、不在错误页回显。
路径约束仅发送当前任务必需且与接收方许可范围相符的派生上下文。

The public model deliberately excludes secret matchers, policy thresholds, encryption topology, and detection rules. Publishing a control boundary should improve reviewability, not create an instruction manual for bypassing it.

3. Receive, construct, execute, return, end

At receipt, context receives a classification and source scope. Construction assembles a task-specific, minimized view rather than passing a complete project snapshot. Execution chooses a permitted local or remote route and applies model, tool, and budget policy. Return processing removes or blocks disallowed output and gives the client a typed result. End-of-run processing expires transient material, records only permitted evidence, and applies any requested deletion or retention schedule.

Each transition can fail closed. A classification gap, route mismatch, revoked authorization, or unavailable local capability should yield a clear constrained outcome—not a silent fallback to a broader audience.

4. Cache, logs, tools, and MCP

Caching is treated as reuse of sensitive material, not merely as performance infrastructure. High-sensitivity bodies are excluded from shared reuse by default; policy, authorization, source version, and purpose changes invalidate any permitted derivative. Logs avoid bodies by default and preserve correlation, policy version, route class, and outcome only to the degree permitted. Tools and MCP servers receive scoped parameters and credentials, never an implicit grant based on model-generated text.

5. Classification, modes, and verification

We evaluate the architecture with a classification matrix, route/mode controls, and verification metrics such as body-bearing-log detection, sensitive reuse rejection, scope denial, and output-period interruption. A metric is meaningful only alongside a policy version and workload context.

级别可进入形式默认去向缓存与日志人工控制
公开/一般内部任务相关原始或派生内容批准常规路径按产品策略,正文/诊断分离常规授权
机密最小字段、摘要、受控检索范围受限模型与工具避免完整复用;脱敏诊断项目级授权
高度敏感去标识化/裁剪派生内容;必要时引用默认隔离路径不缓存正文、不落调试日志、不在报错回显所有者与安全审批例外

6. Assurance boundary and conclusion

This architecture reduces unnecessary exposure and creates evidence for review; it does not make an unsafe source safe, guarantee that every classifier is perfect, or remove the need for application-level authorization. The operational promise is narrower and more useful: sensitive context is deliberately minimized, route-bound, lifetime-bound, tool-scoped, and auditable, with safe refusal when the system cannot establish those conditions.