An IoT security architect wants to implement Bluetooth between two nodes. The Elliptic Curve Diffie- Hellman (ECDH) cipher suite has been identified…

The requirement for the Elliptic Curve Diffie-Hellman (ECDH) cipher suite is met by the LE Secure Connections pairing feature. This feature was introduced specifically in the Bluetooth Core Specification version 4.2. LE Secure Connections uses the FIPS-approved ECDH key exchange protocol to provide robust security against passive eavesdropping and man-in-the-middle (MITM) attacks. Bluetooth versions prior to 4.2, such as 4.0 and 4.1, use a method called LE Legacy Pairing, which does not utilize ECDH and is known to be vulnerable. Therefore, only BLE v4.2 and later versions can satisfy the requirement.

A. Bluetooth Low Energy (BLE) v4.0: This version uses LE Legacy Pairing, which does not support the ECDH cipher suite for key exchange.

C. BLE v4.1: This version also relies on the older LE Legacy Pairing method and lacks the required ECDH support.

D. Any of the BLE versions: This is incorrect because support for ECDH was a specific enhancement introduced in version 4.2, not a feature of earlier versions.

1. Bluetooth Special Interest Group (SIG). Bluetooth Core Specification Version 4.2. Vol. 3

Part H

Section 2.1 "Pairing Methods". This section officially introduces LE Secure Connections

contrasting it with LE legacy pairing. Section 2.3.5.6 "LE Secure Connections pairing phase 2" explicitly details the ECDH public key exchange process.

2. National Institute of Standards and Technology (NIST). NIST Special Publication 800-121 Revision 2: Guide to Bluetooth Security. (May 2017). Section 4.3.2

"LE Secure Connections Pairing

" states

"LE Secure Connections pairing was introduced in Bluetooth v4.2... LE Secure Connections pairing uses Elliptic Curve Diffie-Hellman (ECDH) public key cryptography for key generation..."

3. Padgette

J.

Bahr

J.

Batra

M.

Holtmann

M.

Smith

R.

Chen

L.

& Scarfone

K. (2016). A Survey of Bluetooth Low Energy Security. This academic survey

often cited in security research

notes on page 4: "Bluetooth 4.2 introduced a new pairing procedure called LE Secure Connections... LE Secure Connections uses Elliptic Curve Diffie-Hellman (ECDH) key exchange..." (Available via arXiv:1602.02929).