From 6e1f52131b8c938b70901fbaec56f8f96a28969f Mon Sep 17 00:00:00 2001
From: Justin Traglia <95511699+jtraglia@users.noreply.github.com>
Date: Wed, 13 Mar 2024 13:43:34 -0500
Subject: [PATCH] Remove point-at-infinity for proofs/commitments (#8063)

---
 .../blobs/versions/deneb/BlobSidecar.java              |  2 +-
 .../kzg/src/main/java/tech/pegasys/teku/kzg/KZG.java   |  5 +++--
 .../main/java/tech/pegasys/teku/kzg/KZGCommitment.java |  9 ---------
 .../src/main/java/tech/pegasys/teku/kzg/KZGProof.java  |  3 ---
 .../test/java/tech/pegasys/teku/kzg/CKZG4844Test.java  | 10 +++++++---
 5 files changed, 11 insertions(+), 18 deletions(-)

diff --git a/ethereum/spec/src/main/java/tech/pegasys/teku/spec/datastructures/blobs/versions/deneb/BlobSidecar.java b/ethereum/spec/src/main/java/tech/pegasys/teku/spec/datastructures/blobs/versions/deneb/BlobSidecar.java
index 789bfe01091..4c0598462ca 100644
--- a/ethereum/spec/src/main/java/tech/pegasys/teku/spec/datastructures/blobs/versions/deneb/BlobSidecar.java
+++ b/ethereum/spec/src/main/java/tech/pegasys/teku/spec/datastructures/blobs/versions/deneb/BlobSidecar.java
@@ -135,7 +135,7 @@ public String toLogString() {
         getBlockRoot(),
         getIndex(),
         getBlob().toBriefString(),
-        getKZGCommitment().toHexString(),
+        getKZGCommitment().toAbbreviatedString(),
         getKZGProof().toAbbreviatedString());
   }
 }
diff --git a/infrastructure/kzg/src/main/java/tech/pegasys/teku/kzg/KZG.java b/infrastructure/kzg/src/main/java/tech/pegasys/teku/kzg/KZG.java
index 2451959e1e6..f1b791b4f7c 100644
--- a/infrastructure/kzg/src/main/java/tech/pegasys/teku/kzg/KZG.java
+++ b/infrastructure/kzg/src/main/java/tech/pegasys/teku/kzg/KZG.java
@@ -15,6 +15,7 @@
 
 import java.util.List;
 import org.apache.tuweni.bytes.Bytes;
+import org.apache.tuweni.bytes.Bytes48;
 
 /**
  * This interface specifies all the KZG functions needed for the Deneb specification and is the
@@ -53,13 +54,13 @@ public boolean verifyBlobKzgProofBatch(
 
         @Override
         public KZGCommitment blobToKzgCommitment(final Bytes blob) throws KZGException {
-          return KZGCommitment.infinity();
+          return KZGCommitment.fromBytesCompressed(Bytes48.ZERO);
         }
 
         @Override
         public KZGProof computeBlobKzgProof(final Bytes blob, final KZGCommitment kzgCommitment)
             throws KZGException {
-          return KZGProof.INFINITY;
+          return KZGProof.fromBytesCompressed(Bytes48.ZERO);
         }
       };
 
diff --git a/infrastructure/kzg/src/main/java/tech/pegasys/teku/kzg/KZGCommitment.java b/infrastructure/kzg/src/main/java/tech/pegasys/teku/kzg/KZGCommitment.java
index ad1095d33f9..c63f08b4e84 100644
--- a/infrastructure/kzg/src/main/java/tech/pegasys/teku/kzg/KZGCommitment.java
+++ b/infrastructure/kzg/src/main/java/tech/pegasys/teku/kzg/KZGCommitment.java
@@ -23,15 +23,6 @@
 
 public final class KZGCommitment {
 
-  /**
-   * Creates 0x00..00 for point-at-infinity
-   *
-   * @return point-at-infinity as per the Eth2 spec
-   */
-  public static KZGCommitment infinity() {
-    return KZGCommitment.fromBytesCompressed(Bytes48.ZERO);
-  }
-
   public static KZGCommitment fromHexString(final String hexString) {
     return KZGCommitment.fromBytesCompressed(Bytes48.fromHexString(hexString));
   }
diff --git a/infrastructure/kzg/src/main/java/tech/pegasys/teku/kzg/KZGProof.java b/infrastructure/kzg/src/main/java/tech/pegasys/teku/kzg/KZGProof.java
index ca47486cb83..88844853ffe 100644
--- a/infrastructure/kzg/src/main/java/tech/pegasys/teku/kzg/KZGProof.java
+++ b/infrastructure/kzg/src/main/java/tech/pegasys/teku/kzg/KZGProof.java
@@ -23,9 +23,6 @@
 
 public final class KZGProof {
 
-  /** Creates 0x00..00 for point-at-infinity */
-  public static final KZGProof INFINITY = KZGProof.fromBytesCompressed(Bytes48.ZERO);
-
   public static KZGProof fromHexString(final String hexString) {
     return KZGProof.fromBytesCompressed(Bytes48.fromHexString(hexString));
   }
diff --git a/infrastructure/kzg/src/test/java/tech/pegasys/teku/kzg/CKZG4844Test.java b/infrastructure/kzg/src/test/java/tech/pegasys/teku/kzg/CKZG4844Test.java
index 1933d1ff5e3..8f4895eff1e 100644
--- a/infrastructure/kzg/src/test/java/tech/pegasys/teku/kzg/CKZG4844Test.java
+++ b/infrastructure/kzg/src/test/java/tech/pegasys/teku/kzg/CKZG4844Test.java
@@ -86,12 +86,12 @@ public void testUsageWithoutLoadedTrustedSetup_shouldThrowException() {
                 () ->
                     CKZG.verifyBlobKzgProofBatch(
                         List.of(Bytes.fromHexString("0x", BYTES_PER_BLOB)),
-                        List.of(KZGCommitment.infinity()),
-                        List.of(KZGProof.INFINITY))),
+                        List.of(getSampleCommitment()),
+                        List.of(getSampleProof()))),
             assertThrows(KZGException.class, () -> CKZG.blobToKzgCommitment(Bytes.EMPTY)),
             assertThrows(
                 KZGException.class,
-                () -> CKZG.computeBlobKzgProof(Bytes.EMPTY, KZGCommitment.infinity())));
+                () -> CKZG.computeBlobKzgProof(Bytes.EMPTY, getSampleCommitment())));
 
     assertThat(exceptions)
         .allSatisfy(
@@ -293,6 +293,10 @@ private KZGCommitment getSampleCommitment() {
     return CKZG.blobToKzgCommitment(getSampleBlob());
   }
 
+  private KZGProof getSampleProof() {
+    return CKZG.computeBlobKzgProof(getSampleBlob(), getSampleCommitment());
+  }
+
   private UInt256 randomBLSFieldElement() {
     while (true) {
       final BigInteger attempt = new BigInteger(BLS_MODULUS.bitLength(), RND);