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)
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.
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.
TEEs and HSMs are not absolutely unbreakable, and side-channel attacks, firmware vulnerabilities, and the like remain active research topics.
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 (6)
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.
50%UnverifiedIn LangGraph, the HSM concept is implemented at the code level through subgraphs.
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%UnverifiedTEEs and HSMs are not absolutely unbreakable, and side-channel attacks, firmware vulnerabilities, and the like remain active research topics.
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.
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