Expand description
Constant-pattern compressed Edwards-point decoding.
Ed25519 verification begins by recovering the affine X coordinate from a
compressed Edwards Y coordinate. PointDecodePipe runs that square-root
calculation entirely in hardware. Twenty request contexts share one
initiation-interval-one radix-2^51 multiplier; while one context waits for
its 17-cycle product, another context issues the next operation.
The exponentiation schedule is deliberately simple: a fixed binary
square-and-multiply implementation of (p - 5) / 8. Its 516 field products
per point are independent of input data. A verifier can instantiate one
lane for public keys and one for signature R values, accepting a pair every
516 clocks without external memory.
Structs§
- Point
Decode In - One compressed point and its caller-selected transaction tag.
- Point
Decode Out - Result and flow control from
PointDecodePipe. - Point
Decode Pipe - Twenty-context fixed-schedule Edwards point decoder.
Functions§
- point_
decode_ kernel - State transition for
PointDecodePipe.