diff --git a/packages/engine/src/hash_tag.cairo b/packages/engine/src/hash_tag.cairo
new file mode 100644
index 00000000..03187159
--- /dev/null
+++ b/packages/engine/src/hash_tag.cairo
@@ -0,0 +1,86 @@
+use shinigami_utils::bytecode::hex_to_bytecode;
+use shinigami_utils::hash::sha256_byte_array;
+
+#[derive(Drop)]
+pub enum HashTag {
+    // BIP0340Challenge is the BIP-0340 tag for challenges.
+    Bip0340Challenge,
+    // BIP0340Aux is the BIP-0340 tag for aux data.
+    Bip0340Aux,
+    // BIP0340Nonce is the BIP-0340 tag for nonces.
+    Bip0340Nonce,
+    // TapSighash is the tag used by BIP 341 to generate the sighash
+    // flags.
+    TapSighash,
+    // TagTapLeaf is the message tag prefix used to compute the hash
+    // digest of a tapscript leaf.
+    TapLeaf,
+    // TapBranch is the message tag prefix used to compute the
+    // hash digest of two tap leaves into a taproot branch node.
+    TapBranch,
+    // TapTweak is the message tag prefix used to compute the hash tweak
+    // used to enable a public key to commit to the taproot branch root
+    // for the witness program.
+    TapTweak,
+    // Unknown tag.
+    Other: ByteArray
+}
+
+// TaggedHash implements the tagged hash scheme described in BIP-340. We use
+// sha-256 to bind a message hash to a specific context using a tag:
+// sha256(sha256(tag) || sha256(tag) || msg).
+pub fn tagged_hash(tag: HashTag, msg: @ByteArray) -> ByteArray {
+    // Check if we have precomputed tag to avoid an extra sha256
+    let mut sha_tag: ByteArray = "";
+    match tag {
+        HashTag::Bip0340Challenge => sha_tag
+            .append(
+                @hex_to_bytecode(
+                    @"0x7bb52d7a9fef58323eb1bf7a407db382d2f3f2d81bb1224f49fe518f6d48d37c"
+                )
+            ),
+        HashTag::Bip0340Aux => sha_tag
+            .append(
+                @hex_to_bytecode(
+                    @"0xf1ef4e5ec063cada6d94cafa9d987ea069265839ecc11f972d77a52ed8c1cc90"
+                )
+            ),
+        HashTag::Bip0340Nonce => sha_tag
+            .append(
+                @hex_to_bytecode(
+                    @"0x07497734a79bcb355b9b8c7d034f121cf434d73ef72dda19870061fb52bfeb2f"
+                )
+            ),
+        HashTag::TapSighash => sha_tag
+            .append(
+                @hex_to_bytecode(
+                    @"0xf40a48df4b2a70c8b4924bf2654661ed3d95fd66a313eb87237597c628e4a031"
+                )
+            ),
+        HashTag::TapLeaf => sha_tag
+            .append(
+                @hex_to_bytecode(
+                    @"0xaeea8fdc4208983105734b58081d1e2638d35f1cb54008d4d357ca03be78e9ee"
+                )
+            ),
+        HashTag::TapBranch => sha_tag
+            .append(
+                @hex_to_bytecode(
+                    @"0x1941a1f2e56eb95fa2a9f194be5c01f7216f33ed82b091463490d05bf516a015"
+                )
+            ),
+        HashTag::TapTweak => sha_tag
+            .append(
+                @hex_to_bytecode(
+                    @"0xe80fe1639c9ca050e3af1b39c143c63e429cbceb15d940fbb5c5a1f4af57c5e9"
+                )
+            ),
+        HashTag::Other(bytes) => sha_tag.append(@sha256_byte_array(@bytes))
+    };
+
+    // h = sha256(sha256(tag) || sha256(tag) || msg)
+    let mut h: ByteArray = sha_tag.clone();
+    h.append(@sha_tag);
+    h.append(msg);
+    return sha256_byte_array(@h);
+}
diff --git a/packages/engine/src/lib.cairo b/packages/engine/src/lib.cairo
index 27da824a..595940f3 100644
--- a/packages/engine/src/lib.cairo
+++ b/packages/engine/src/lib.cairo
@@ -5,6 +5,7 @@ pub mod cond_stack;
 pub mod witness;
 pub mod taproot;
 pub mod hash_cache;
+pub mod hash_tag;
 pub mod errors;
 pub mod opcodes {
     pub mod opcodes;