chore: VidScheme::Commit assoc type support TaggedBase64 conversion (#…

…458) * add TODO comment for #393 * add trait bounds to VidScheme::Commit, support it in advz impl
EspressoSystems · Jan 12, 2024 · 8d071e2 · 8d071e2
1 parent 7e906cf
commit 8d071e2
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Showing 3 changed files with 29 additions and 8 deletions.
diff --git a/primitives/src/merkle_tree/hasher.rs b/primitives/src/merkle_tree/hasher.rs
@@ -50,7 +50,7 @@ use digest::{
     crypto_common::{generic_array::ArrayLength, Output},
     Digest, OutputSizeUser,
 };
-use serde::{Deserialize, Serialize};
+use tagged_base64::tagged;
 use typenum::U3;
 
 /// Merkle tree generic over [`Digest`] hasher `H`.
@@ -161,8 +161,7 @@ where
 }
 
 /// Newtype wrapper for hash output that impls [`NodeValue`](super::NodeValue).
-#[derive(Derivative, Deserialize, Serialize)]
-#[serde(bound = "Output<H>: Serialize + for<'a> Deserialize<'a>")]
+#[derive(Derivative)]
 #[derivative(
     Clone(bound = ""),
     Copy(bound = "<<H as OutputSizeUser>::OutputSize as ArrayLength<u8>>::ArrayType: Copy"),
@@ -174,6 +173,7 @@ where
     PartialEq(bound = ""),
     PartialOrd(bound = "")
 )]
+#[tagged("HASH")]
 pub struct HasherNode<H>(Output<H>)
 where
     H: Digest;

diff --git a/primitives/src/vid.rs b/primitives/src/vid.rs
@@ -6,14 +6,31 @@
 
 //! Trait and implementation for a Verifiable Information Retrieval (VID).
 /// See <https://arxiv.org/abs/2111.12323> section 1.3--1.4 for intro to VID semantics.
-use ark_std::{error::Error, fmt::Debug, hash::Hash, string::String, vec::Vec};
+use ark_std::{
+    error::Error,
+    fmt::{Debug, Display},
+    hash::Hash,
+    string::String,
+    vec::Vec,
+};
 use displaydoc::Display;
 use serde::{de::DeserializeOwned, Deserialize, Serialize};
+use tagged_base64::TaggedBase64;
 
 /// VID: Verifiable Information Dispersal
 pub trait VidScheme {
     /// Payload commitment.
-    type Commit: Clone + Debug + DeserializeOwned + Eq + PartialEq + Hash + Serialize + Sync; // TODO https://github.com/EspressoSystems/jellyfish/issues/253
+    type Commit: Clone
+        + Debug
+        + Display
+        + DeserializeOwned
+        + Eq
+        + PartialEq
+        + Hash
+        + Serialize
+        + Sync
+        + for<'a> TryFrom<&'a TaggedBase64>
+        + Into<TaggedBase64>; // TODO https://github.com/EspressoSystems/jellyfish/issues/253
 
     /// Share-specific data sent to a storage node.
     type Share: Clone + Debug + DeserializeOwned + Eq + PartialEq + Hash + Serialize + Sync; // TODO https://github.com/EspressoSystems/jellyfish/issues/253

diff --git a/primitives/src/vid/advz.rs b/primitives/src/vid/advz.rs
@@ -12,7 +12,7 @@ use super::{vid, VidDisperse, VidError, VidResult, VidScheme};
 use crate::{
     alloc::string::ToString,
     merkle_tree::{
-        hasher::{HasherDigest, HasherMerkleTree},
+        hasher::{HasherDigest, HasherMerkleTree, HasherNode},
         MerkleCommitment, MerkleTreeScheme,
     },
     pcs::{
@@ -100,6 +100,8 @@ where
         num_storage_nodes: usize,
         srs: impl Borrow<KzgSrs<E>>,
     ) -> VidResult<Self> {
+        // TODO support any degree, give multiple shares to nodes if needed
+        // https://github.com/EspressoSystems/jellyfish/issues/393
         if num_storage_nodes < payload_chunk_size {
             return Err(VidError::Argument(format!(
                 "payload_chunk_size {} exceeds num_storage_nodes {}",
@@ -196,7 +198,9 @@ where
     E: Pairing,
     H: HasherDigest,
 {
-    type Commit = Output<H>;
+    // use HasherNode<H> instead of Output<H> to easily meet trait bounds
+    type Commit = HasherNode<H>;
+
     type Share = Share<E, H>;
     type Common = Common<E, H>;
 
@@ -550,7 +554,7 @@ where
                 .serialize_uncompressed(&mut hasher)
                 .map_err(vid)?;
         }
-        Ok(hasher.finalize())
+        Ok(hasher.finalize().into())
     }
 }