HSM
An extension of FSM that allows nested sub-state machines within states, originating from the Statecharts theory proposed by David Harel in 1987. Parent states can handle bubbling events, enabling behavioral inheritance and reuse and resolving the FSM state explosion problem. In agent design, it is used to manage complex tool-calling flows and multi-agent systems.
Timeline (last 90 days)
Signature migration is more difficult than key exchange, for reasons including size issues, trust anchors, long-lived signature artifacts and hardware limitations.
A hierarchical state machine (HSM) is an extension of the FSM, originating from the Statecharts theory proposed by David Harel in 1987 and later becoming the theoretical basis of UML state diagrams, and it allows a state to nest sub-state machines within it.
In LangGraph, the HSM concept is implemented at the code level through subgraphs.
TEEs and HSMs are not absolutely unbreakable, and side-channel attacks, firmware vulnerabilities, and the like remain active research topics.
Passkeys' private keys are stored in the user device's trusted execution environment (TEE) or hardware security module (HSM), and the server only stores the public key.
An HSM is a standalone dedicated security chip, commonly found in phones' secure elements, laptops' TPM modules, and external hardware keys.
In AI payment systems, the widely adopted security paradigm is that the language model is responsible only for reasoning, explanation and generating candidate actions, while actual key management, signing and fund transfers must be performed by controlled backend services (such as HSMs, custodial wallets or policy engines) after passing permission checks.
All Facts (8)
Signature migration is more difficult than key exchange, for reasons including size issues, trust anchors, long-lived signature artifacts and hardware limitations.
50%UnverifiedIn LangGraph, the HSM concept is implemented at the code level through subgraphs.
50%UnverifiedA hierarchical state machine (HSM) is an extension of the FSM, originating from the Statecharts theory proposed by David Harel in 1987 and later becoming the theoretical basis of UML state diagrams, and it allows a state to nest sub-state machines within it.
50%UnverifiedTEEs and HSMs are not absolutely unbreakable, and side-channel attacks, firmware vulnerabilities, and the like remain active research topics.
50%UnverifiedPasskeys' private keys are stored in the user device's trusted execution environment (TEE) or hardware security module (HSM), and the server only stores the public key.
50%UnverifiedAn HSM is a standalone dedicated security chip, commonly found in phones' secure elements, laptops' TPM modules, and external hardware keys.
50%UnverifiedIn AI payment systems, the widely adopted security paradigm is that the language model is responsible only for reasoning, explanation and generating candidate actions, while actual key management, signing and fund transfers must be performed by controlled backend services (such as HSMs, custodial wallets or policy engines) after passing permission checks.
50%UnverifiedSSH密钥认证过程中私钥永远不离开本地设备，即便服务器被入侵，攻击者获得的公钥也无法反推私钥
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