feat: cache verifying key + commitments (recursion opt)

bench_vs/lambda/deserialize-only/src/main.rs

@@ -1,7 +1,7 @@
 //! Deserialize-only counterpart to the recursion guest.
 //!
 //! Reads the same private-input blob as `recursion-bench`, postcard-decodes
-//! `(VmProof, Vec<u8>, ProofOptions)`, then commits success
+//! `(VmProof, Vec<u8>, ProofOptions, VmVerifyingKey)`, then commits success
 //! and halts — without ever calling `verify_with_options`. The cycle delta
 //! between this guest and `recursion-bench` is the actual cost of the STARK
 //! verifier inside the VM (everything else being equal).
@@ -16,7 +16,7 @@ use core::arch::asm;
 use core::panic::PanicInfo;
 
 use embedded_alloc::TlsfHeap as Heap;
-use lambda_vm_prover::{ProofOptions, VmProof};
+use lambda_vm_prover::{ProofOptions, VmProof, VmVerifyingKey};
 // Required to pull in the riscv crate's critical-section implementation.
 use riscv as _;
 
@@ -75,7 +75,7 @@ pub fn main() -> ! {
     init_allocator();
 
     let blob = read_private_input();
-    let decoded: (VmProof, Vec<u8>, ProofOptions) =
+    let decoded: (VmProof, Vec<u8>, ProofOptions, VmVerifyingKey) =
         postcard::from_bytes(blob).expect("failed to deserialize");
 
     // Force the commit byte to depend on the actually-decoded value. Without
@@ -86,7 +86,8 @@ pub fn main() -> ! {
     // to a deep field of the decoded value, the decode has to run.
     let proof_options_byte = decoded.2.blowup_factor;
     let inner_elf_byte = *decoded.1.first().unwrap_or(&0);
-    let marker = proof_options_byte ^ inner_elf_byte;
+    let vkey_byte = decoded.3.bitwise[0];
+    let marker = proof_options_byte ^ inner_elf_byte ^ vkey_byte;
 
     commit(&[marker]);
     halt()

bench_vs/lambda/recursion/src/main.rs

@@ -8,7 +8,7 @@ use core::arch::asm;
 use core::panic::PanicInfo;
 
 use embedded_alloc::TlsfHeap as Heap;
-use lambda_vm_prover::{ProofOptions, VmProof};
+use lambda_vm_prover::{ProofOptions, VmProof, VmVerifyingKey};
 // Required to pull in the riscv crate's critical-section implementation.
 use riscv as _;
 
@@ -67,18 +67,29 @@ fn halt() -> ! {
 }
 
 /// Private input layout (postcard-encoded):
-///   (VmProof, Vec<u8>, ProofOptions)
-/// where the `Vec<u8>` holds the inner program's ELF bytes and the
-/// `ProofOptions` specifies the parameters the inner prover used.
+///   (VmProof, Vec<u8>, ProofOptions, VmVerifyingKey)
+/// where the `Vec<u8>` holds the inner program's ELF bytes, the
+/// `ProofOptions` specifies the parameters the inner prover used, and the
+/// `VmVerifyingKey` carries the host-derived bitwise preprocessed commitment
+/// so the guest can skip the ~87% of verifier cycles that would otherwise be
+/// spent recomputing it from scratch.
 #[unsafe(no_mangle)]
 pub fn main() -> ! {
     init_allocator();
 
     let blob = read_private_input();
-    let (vm_proof, inner_elf, options): (VmProof, Vec<u8>, ProofOptions) =
+    let (vm_proof, inner_elf, options, vkey): (VmProof, Vec<u8>, ProofOptions, VmVerifyingKey) =
         postcard::from_bytes(blob).expect("failed to deserialize recursion input");
 
-    let ok = lambda_vm_prover::verify_with_options(&vm_proof, &inner_elf, &options, None, None)
+    let ok =
+        lambda_vm_prover::verify_with_options_with_vkey(
+            &vm_proof,
+            &inner_elf,
+            &options,
+            None,
+            None,
+            Some(&vkey),
+        )
         .expect("verify errored");
     assert!(ok, "inner proof failed verification");
 

prover/Cargo.toml

@@ -30,6 +30,7 @@ rayon = { version = "1.8.0", optional = true }
 sysinfo = { version = "0.31", default-features = false, features = ["system"], optional = true }
 log = "0.4"
 sha3 = { version = "0.10.8", default-features = false }
+postcard = { version = "1.0", default-features = false, features = ["alloc"] }
 
 [dev-dependencies]
 env_logger = "*"