XIP4003C: X25519 and Ed25519

Very compact IP core designed for efficient X25519 key exchange and EdDSA

XIP4003C supports the following five operations: Constant-time x-coordinate-only scalar multiplication for X25519 key exchange with the Montgomery ladder algorithm, Constant-time fixed-base scalar multiplication for Ed25519 signature generation, Double-base scalar multiplication for Ed25519 signature verification, Point compression/decompression, and other modular arithmetic for generating and verifying Ed25519 signatures.

Easy integration with other FPGA logic, as the functionality of XIP4003C does not rely on any FPGA family specific features.


  • Minimal Resource Requirements: The entire XIP4003C requires 2804 Logic Elements (Lattice ECP5) and uses only 1-2 multipliers/DSP Blocks and 1-2 memory blocks in a typical FPGA implementation.
  • Constant Latency: The execution time of XIP4003C is independent of the key value, and consequently provides protection against timing-based side-channel attacks.
  • Performance: Despite its small size, XIP4003C can support more than 100 key exchange or digital signature operations per second.
  • Standard Compliance: XIP4003C is compliant with RFC 7748, RFC 8032, and the draft version of FIPS 186-5. XIP4003C can be used in many public-key protocols including IKEv2 (RFC 8031) and TLS 1.3 (RFC 8446).

Block Diagram

Internal high-level block diagram of XIP4003C

Resource Usage and Performance

FPGA family Resources Output bit rate
Lattice ECP5 2804 4LUTs, 1 EBR, 1 MULT18 150.60 MHz

Resource usage and performance of XIP4003C on Lattice ECP5 FPGA family. On request, the resource estimates can also be supplied for other Lattice FPGA families.

Ordering Information

Please contact sales@xiphera.com for pricing and your preferred delivery method. XIP4003C can be shipped in a number of formats, including netlist, source code, or encrypted source code. Additionally, a comprehensive VHDL testbench and a detailed datasheet are included.

You can download the Lattice Product Brief from https://xiphera.com/partners/lattice/XIP4003C_PB_lattice.pdf


Information Resources
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Xiphera Lattice IP Core Metrics
1.0 8/5/2021 PDF 41.2 KB

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