All UDS services

Secured Data Transmission

0x84

The Secured Data Transmission service wraps any UDS service request in a secured envelope, providing encryption, signing, and anti-replay protection for sensitive diagnostic operations.

✕Negative response codes
0x13

Request

SID 0x84 · 9 bytes
Len (bits)
Parameter description
Value (hex)
8
Secured Data Transmission SID
0x84
8
reservedReserved bits, fixed to zero.
1
reservedReserved bits, fixed to zero.
1
signatureRequestedIndicates whether the server should include a signature in the response.
1
isSignedIndicates whether this message includes a digital signature.
1
isEncryptedIndicates whether the payload of this message is encrypted.
1
preEstablishedKeyUsedIndicates whether a previously established encryption key is reused for this message.
2
reservedReserved bits, fixed to zero.
1
isRequestMessageIndicates this is a request message (always set to 1 for requests).
8
SignatureEncryptionCalculationIdentifies the cryptographic algorithms used for signing and encryption.
0x00-0xFF
16
signatureLengthByte length of the signature field appended to the message.
0x0000-0xFFFF
16
antiReplayCounterMonotonic counter value used to detect and prevent replay attacks.
0x0000-0xFFFF
8
internalMessageServiceRequestIDService Identifier (SID) of the UDS service being secured.
0x00-0xFF
n*
8
serviceSpecificParametersPayload bytes of the secured UDS service request.Optional
0x00-0xFF
m*
8
signatureDigital signature computed over the message content.Optional
0x00-0xFF

n = Number of service-specific parameter bytes

m = value of signatureLength

Positive response

SID 0xC4
Len (bits)
Parameter description
Value (hex)
8
Secured Data Transmission SID
0xC4
8
reservedReserved bits, fixed to zero.
1
reservedReserved bits, fixed to zero.
1
signatureRequestedIndicates whether a signature was requested.
1
isSignedIndicates whether this response includes a digital signature.
1
isEncryptedIndicates whether the response payload is encrypted.
1
preEstablishedKeyUsedIndicates whether a previously established encryption key was used.
2
reservedReserved bits, fixed to zero.
1
isRequestMessageIndicates this is a response message (always set to 0 for responses).
8
SignatureEncryptionCalculationIdentifies the cryptographic algorithms used for signing and encryption.
0x00-0xFF
16
signatureLengthByte length of the signature field appended to the response.
0x0000-0xFFFF
16
antiReplayCounterMonotonic counter value for replay attack prevention.
0x0000-0xFFFF
8
internalMessageServiceResponseIDService Identifier (SID + 0x40) of the secured UDS service response.
0x00-0xFF
n*
8
serviceSpecificParametersPayload bytes of the secured UDS service response.Optional
0x00-0xFF
m*
8
signatureDigital signature computed over the response content.Optional
0x00-0xFF

n = Number of service-specific parameter bytes

m = value of signatureLength

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