Abstract:
PURPOSE: An apparatus including function of authenticating a JTAC(Joint Test Action Group) and an authenticating method thereof are provided to minimize the risks, which may happen when modifying a TAP controller or the modification of the TAP controller is not required, by using a JTAG access circuit that determines the access of the JTAG device. CONSTITUTION: A JTAG(Joint Test Action Group) detector(211) generates an activated interface detection signal in the connection to a JTAG device. A JTAG security circuit(212) inactivates an internal bus line and/or internal devices by responding to the interface detection signal. The JTAG security circuit activates the internal bus line and/or the internal devices by comparing the recognized ID data of the JTAG with reference data.
Abstract:
An electronic device for security boot up and a method for computation hash vale and boot-up operation thereof are provided to decrease a production cost and a chip size by reducing hash code stored in the E-fuse memory. A flash memory(120) stores the boot code and public key. A processor(111) enforces the boot code. An E-fuse memory(113) stores the first hash value. A block encrypting unit(115) calculates the second Hash value of the public key with the block cryptographic algorithm. The block cryptographic algorithm uses a part of the public key as the first input value. The first hash value stored in the second memory is the value hashing the public key with the block cryptographic algorithm. The boot code comprises command codes. The command code determines whether a processor calculates the Hash value of the public key stored in the nonvolatile memory, reads the Hash value stored in E-fuse memory, and compares the calculated Hash value with the Hash value read from the E-fuse memory. When the calculated Hash value matches with the Hash value read from the E-fuse, the command code enforces the processor to execute a boot code.
Abstract:
본 발명에 따른 인코더의 인코딩 방법은: 입력된 원-핫 비트들을 이용하여 상위 비트들을 위한 제 1 원-핫 비트들 및 하위 비트들을 위한 제 2 원-핫 비트들을 발생하는 단계; 및 크로스-커넥션을 이용하는 제 1 논리 연산을 통하여 상기 제 1 원-핫 비트들을 상기 상위 비트들 및 상기 상위 비트들에 상보적인 상보 상위 비트들로 인코딩하고, 크로스-커넥션을 이용하는 제 2 논리 연산을 통하여 상기 제 2 원-핫 비트들을 상기 하위 비트들 및 상기 하위 비트들에 상보적인 상보 하위 비트들로 인코딩하는 단계를 포함한다.