ARM Security 용어집

핵심 용어 ISO 11179 형식 정의.

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E — EL / Enclave

EL (Exception Level)

Definition. ARMv8의 권한 계층으로 EL0 (user) → EL1 (kernel/OS) → EL2 (hypervisor) → EL3 (secure monitor)의 4단계.

Source. ARMv8-A Architecture Reference Manual.

Related. Exception, ERET, SVC/HVC/SMC.

See also. Module 01

Secure Enclave

Definition. 별도 processor + 전용 RAM + 전용 crypto engine으로 물리적으로 격리된 보안 영역으로, TrustZone의 한계를 극복.

Source. Apple SEP, Google Titan M, Samsung Knox vault.

Related. TEE, mutual distrust.

See also. Module 02A

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G — GIC

GIC (Generic Interrupt Controller)

Definition. ARM의 표준 인터럽트 컨트롤러로, GIC v3는 Group 0 (secure) / Group 1 (non-secure) 분리를 지원.

Source. ARM GIC v3 Architecture Specification.

Related. SGI/PPI/SPI, IRQ/FIQ.

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N — NS bit

NS (Non-Secure) bit

Definition. PSTATE의 1-bit field로, 현재 instruction이 발급된 World (Secure=0, Non-Secure=1)를 표시. 메모리/peripheral access마다 propagate.

Source. ARMv8-A.

Related. TrustZone, world switch.

See also. Module 01

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S — SMC / Secure Monitor

SMC (Secure Monitor Call)

Definition. EL3로 진입하기 위한 ARM instruction으로, Non-Secure World에서 Secure World로 전환할 때 사용.

Source. ARMv8-A.

Related. SVC (EL1 syscall), HVC (EL2 hypervisor call), Secure Monitor.

See also. Module 02

Secure Monitor

Definition. EL3에 영구 거주하는 software (BL31 / ATF)로, world switch 시 register save/restore + policy enforcement 담당.

Source. ARM Trusted Firmware.

Related. BL31, EL3, world switch.

See also. Module 02

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T — TEE / TrustZone / TZASC / TZPC

TEE (Trusted Execution Environment)

Definition. 일반 OS와 격리된 보안 실행 환경으로, ARM TrustZone, SGX, SEP 등이 구현.

Source. GlobalPlatform TEE specification.

Related. REE (Rich Execution Environment), Trusty, OP-TEE.

TrustZone

Definition. ARM의 CPU 기반 hardware 보안 확장으로, Secure World와 Non-Secure World의 수평적 격리를 제공.

Source. ARM TrustZone documentation.

Related. NS bit, World switch, EL3.

See also. Module 01

TZASC (TrustZone Address Space Controller)

Definition. DRAM 영역을 Secure / Non-Secure로 분할하는 SoC peripheral로, 비secure access를 차단.

Source. ARM TZC-400/TZC-500 spec.

See also. Module 02

TZPC (TrustZone Protection Controller)

Definition. SoC peripheral마다 Secure / Non-Secure 설정을 관리하는 controller.

Source. ARM TZPC spec.

See also. Module 02

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W — World Switch

World Switch

Definition. Secure World ↔ Non-Secure World 전환 과정으로, 반드시 EL3 Secure Monitor를 경유.

Source. ARMv8-A.

Flow. SMC → trap to EL3 → save context → switch NS bit → restore other world context → ERET.

See also. Module 02

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추가 약어

약어	풀네임	의미
ATF	ARM Trusted Firmware	EL3 secure monitor 구현체
OP-TEE	Open Portable TEE	open source TEE OS
SGX	Software Guard Extensions	Intel의 enclave (TrustZone과 다른 model)
SEP	Secure Enclave Processor	Apple의 secure enclave
HVC	Hypervisor Call	EL2 진입 instruction
SVC	Supervisor Call	EL1 진입 (syscall)
REE	Rich Execution Environment	일반 OS 영역 (TEE의 반대)