196 Fast Authentication Accelerator
196 : Fast Authentication Accelerator
- Author: Nagaraj
- Description: A hardware IP block that performs low-latency ECDSA verification for V2X communication. Authenticates digital signatures in under 1 ms, meeting IEEE 1609.2 automotive security requirements.
- GitHub repository
- Open in 3D viewer
- Clock: 50000000 Hz
Fast Authentication Accelerator
Low-Latency Digital Signature Verification for V2X Communication
How it works
V2X (Vehicle-to-Everything) communication requires every transmitted message to be digitally authenticated in real time. At highway speeds this must happen in under 1 millisecond — far too fast for general-purpose software.
This project implements a dedicated hardware IP block that performs ECDSA (Elliptic Curve Digital Signature Algorithm) verification, the industry standard for V2X security defined in IEEE 1609.2.
How to test
Architecture
V2X Packet Input ui_in[7:0] │ ┌──────▼───────┐ ┌──────────────┐ │ Auth │────▶│ Key Manager │ │ Coprocessor │ │ (cert cache)│ └──────┬───────┘ └──────────────┘ │ ┌──────▼────────────────────────┐ │ ECC Core │ │ ┌────────────────────────┐ │ │ │ Modular Inverse │ │ s⁻¹ mod n │ ├────────────────────────┤ │ │ │ Scalar Multiplier │ │ u1, u2 │ ├────────────────────────┤ │ │ │ Point Multiplier │ │ u1·G + u2·Q │ ├────────────────────────┤ │ │ │ Comparator │ │ R'.x mod n =?= r │ └────────────────────────┘ │ └──────┬────────────────────────┘ │ uo_out[0] auth_valid ✔ uo_out[1] auth_reject ✖
| Block | Function |
|---|---|
| Auth Coprocessor | Protocol parsing, FSM control, IEEE 1609.2 packet handling |
| Key Manager | Certificate and session key cache |
| Modular Inverse | Computes s⁻¹ mod n using Fermat's Little Theorem |
| Scalar Multiplier | Computes u1 = e·w mod n and u2 = r·w mod n |
| Point Multiplier | Computes u1·G + u2·Q using double-and-add |
| Comparator | Checks R'.x mod n == r to accept or reject |
ECDSA Verification Steps
- Receive V2X packet: message hash
e, signature(r, s), public keyQ - Compute
w = s⁻¹ mod n - Compute
u1 = e·w mod nandu2 = r·w mod n - Compute point
R' = u1·G + u2·Q - Compare
R'.x mod nwithr— match = VALID, mismatch = REJECT
How to test
Pin Usage
| Pin | Name | Description |
|---|---|---|
ui_in[7:0] |
data_in |
Serialised packet/key bytes |
ui_in[0] |
start |
Pulse HIGH to begin (in control mode) |
ui_in[1] |
soft_rst |
Soft reset |
ui_in[3:2] |
mode |
00=verify, 01=load_key |
uo_out[0] |
auth_valid |
HIGH = accepted |
uo_out[1] |
auth_reject |
HIGH = rejected |
uo_out[2] |
busy |
HIGH = computing |
uo_out[3] |
ecc_done |
Pulse on each ECC step done |
uo_out[4] |
key_loaded |
HIGH = key ready |
uo_out[5] |
packet_ready |
HIGH = packet received |
Operation Sequence
- Apply
rst_nreset - Set
ui_in[3:2]=01(load_key mode), pulseui_in[0](start) - Stream 64 key bytes on
ui_in[7:0] - Wait for
uo_out[4](key_loaded) = HIGH - Set
ui_in[3:2]=00(verify mode), pulseui_in[0](start) - Stream packet bytes on
ui_in[7:0] - Wait for
uo_out[2](busy) = LOW - Read
uo_out[0](auth_valid) oruo_out[1](auth_reject)
Simulation
cd test/
make
External hardware
None required.
References
- IEEE 1609.2 — V2X Security Services
- FIPS 186-4 — Digital Signature Standard, NIST
- AEC-Q100 — Automotive IC reliability
- RFC 6979 — Deterministic ECDSA
IO
| # | Input | Output | Bidirectional |
|---|---|---|---|
| 0 | start - Pulse HIGH to begin | auth_valid - HIGH when signature verified | |
| 1 | soft_rst - Soft reset active HIGH | auth_reject - HIGH when signature rejected | |
| 2 | mode0 - Mode select bit 0 | busy - HIGH while processing | |
| 3 | mode1 - Mode select bit 1 | ecc_done - Pulses when ECC step done | |
| 4 | data_in bit 4 | key_loaded - HIGH when key loaded | |
| 5 | data_in bit 5 | packet_ready - HIGH when packet received | |
| 6 | data_in bit 6 | ||
| 7 | data_in bit 7 |