@@ -0,0 +1,13 @@
+## 0.1.1 (2023-02-06)
+
+- Introduced `merge_in_domain` for the RPO hash function, to allow using a specified domain value in the second capacity register when hashing two digests together.
+- Added a simple sparse Merkle tree implementation.
+- Added re-exports of Winterfell RandomCoin and RandomCoinError.
+
+## 0.1.0 (2022-12-02)
+
+- Initial release on crates.io containing the cryptographic primitives used in Miden VM and the Miden Rollup.
+- Hash module with the BLAKE3 and Rescue Prime Optimized hash functions.
+    - BLAKE3 is implemented with 256-bit, 192-bit, or 160-bit output. 
+    - RPO is implemented with 256-bit output.
+- Merkle module, with a set of data structures related to Merkle trees, implemented using the RPO hash function.

@@ -1,6 +1,6 @@
 [package]
 name = "miden-crypto"
-version = "0.1.0"
+version = "0.1.1"
 description="Miden Cryptographic primitives"
 authors = ["miden contributors"]
 readme="README.md"

@@ -294,6 +294,28 @@ pub fn hash_elements<E: FieldElement<BaseField = Felt>>(elements: &[E]) -> RpoDigest {
         <Self as ElementHasher>::hash_elements(elements)
     }
 
+    // DOMAIN IDENTIFIER
+    // --------------------------------------------------------------------------------------------
+
+    /// Returns a hash of two digests and a domain identifier.
+    pub fn merge_in_domain(values: &[RpoDigest; 2], domain: Felt) -> RpoDigest {
+        // initialize the state by copying the digest elements into the rate portion of the state
+        // (8 total elements), and set the capacity elements to 0.
+        let mut state = [ZERO; STATE_WIDTH];
+        let it = RpoDigest::digests_as_elements(values.iter());
+        for (i, v) in it.enumerate() {
+            state[RATE_RANGE.start + i] = *v;
+        }
+
+        // set the second capacity element to the domain value. The first capacity element is used
+        // for padding purposes.
+        state[CAPACITY_RANGE.start + 1] = domain;
+
+        // apply the RPO permutation and return the first four elements of the state
+        Self::apply_permutation(&mut state);
+        RpoDigest::new(state[DIGEST_RANGE].try_into().unwrap())
+    }
+
     // RESCUE PERMUTATION
     // --------------------------------------------------------------------------------------------
 

@@ -1,5 +1,6 @@
 use super::{
-    Felt, FieldElement, Hasher, Rpo256, RpoDigest, StarkField, ALPHA, INV_ALPHA, STATE_WIDTH, ZERO,
+    Felt, FieldElement, Hasher, Rpo256, RpoDigest, StarkField, ALPHA, INV_ALPHA, ONE, STATE_WIDTH,
+    ZERO,
 };
 use core::convert::TryInto;
 use rand_utils::rand_value;
@@ -49,6 +50,33 @@
     let m_result = Rpo256::merge(&digests);
     let h_result = Rpo256::hash_elements(&elements);
     assert_eq!(m_result, h_result);
+}
+
+#[test]
+fn merge_vs_merge_in_domain() {
+    let elements = [Felt::new(rand_value()); 8];
+
+    let digests: [RpoDigest; 2] = [
+        RpoDigest::new(elements[..4].try_into().unwrap()),
+        RpoDigest::new(elements[4..].try_into().unwrap()),
+    ];
+    let merge_result = Rpo256::merge(&digests);
+
+    // ------------- merge with domain = 0 ----------------------------------------------------------
+
+    // set domain to ZERO. This should not change the result.
+    let domain = ZERO;
+
+    let merge_in_domain_result = Rpo256::merge_in_domain(&digests, domain);
+    assert_eq!(merge_result, merge_in_domain_result);
+
+    // ------------- merge with domain = 1 ----------------------------------------------------------
+
+    // set domain to ONE. This should change the result.
+    let domain = ONE;
+
+    let merge_in_domain_result = Rpo256::merge_in_domain(&digests, domain);
+    assert_ne!(merge_result, merge_in_domain_result);
 }
 
 #[test]

@@ -10,6 +10,8 @@
 // RE-EXPORTS
 // ================================================================================================
 
+pub use winter_crypto::{RandomCoin, RandomCoinError};
+
 pub use winter_math::{fields::f64::BaseElement as Felt, FieldElement, StarkField};
 
 pub mod utils {

@@ -4,7 +4,7 @@ // MERKLE PATH SET
 // ================================================================================================
 
 /// A set of Merkle paths.
-#[derive(Clone, Debug)]
+#[derive(Debug, Clone, PartialEq, Eq)]
 pub struct MerklePathSet {
     root: Word,
     total_depth: u32,

@@ -7,7 +7,7 @@ // MERKLE TREE
 // ================================================================================================
 
 /// A fully-balanced binary Merkle tree (i.e., a tree where the number of leaves is a power of two).
-#[derive(Clone, Debug)]
+#[derive(Debug, Clone, PartialEq, Eq)]
 pub struct MerkleTree {
     nodes: Vec<Word>,
 }

@@ -9,7 +9,7 @@
 /// A sparse Merkle tree with 63-bit keys and 4-element leaf values, without compaction.
 /// Manipulation and retrieval of leaves and internal nodes is provided by its internal `Store`.
 /// The root of the tree is recomputed on each new leaf update.
-#[derive(Clone, Debug)]
+#[derive(Debug, Clone, PartialEq, Eq)]
 pub struct SimpleSmt {
     root: Word,
     depth: u32,
@@ -186,7 +186,7 @@ /// A data store for sparse Merkle tree key-value pairs.
 /// Leaves and branch nodes are stored separately in B-tree maps, indexed by key and (key, depth)
 /// respectively. Hashes for blank subtrees at each layer are stored in `empty_hashes`, beginning
 /// with the root hash of an empty tree, and ending with the zero value of a leaf node.
-#[derive(Clone, Debug)]
+#[derive(Debug, Clone, PartialEq, Eq)]
 struct Store {
     branches: BTreeMap<(u64, u32), BranchNode>,
     leaves: BTreeMap<u64, Word>,
@@ -194,7 +194,7 @@ empty_hashes: Vec<RpoDigest>,
     depth: u32,
 }
 
-#[derive(Clone, Debug, Default)]
+#[derive(Debug, Default, Clone, PartialEq, Eq)]
 struct BranchNode {
     left: RpoDigest,
     right: RpoDigest,