chore: add comprehensive docstring to compress_with_cryptography (hiero-ledger#1632)

Signed-off-by: Ashhar Ahmad Khan <145142826+AshharAhmadKhan@users.noreply.github.com>
Signed-off-by: Ashhar Ahmad Khan <itzashhar@gmail.com>

Author: AshharAhmadKhan

CHANGELOG.md

@@ -132,6 +132,9 @@ This changelog is based on [Keep a Changelog](https://keepachangelog.com/en/1.1.
 - Add automated bot to recommend next issues to contributors after their first PR merge (#1380)
 - Added dry-run support and refactored `.github/workflows/bot-workflows.yml` to use dedicated script `.github/scripts/bot-workflows.js` for improved maintainability and testability. (`#1288`)
 
+### Documentation
+- Added comprehensive docstring to `compress_with_cryptography` function (#1626)
+
 ### Changed
 - Refactored `examples/consensus/topic_create_transaction.py` to use `Client.from_env()` (#1611)
 - Updated GitHub Actions setup-node action to v6.2.0.

src/hiero_sdk_python/utils/crypto_utils.py

@@ -56,8 +56,21 @@ def decompress_point(data: bytes) -> Tuple[int, int]:
 
 def compress_with_cryptography(encoded: bytes) -> bytes:
     """
-    Takes either a 33-byte compressed or 65-byte uncompressed,
-    returns a 33-byte compressed via cryptography.
+    Compress an elliptic curve public key to SEC1 compressed format.
+
+    Accepts either a 33-byte compressed or 65-byte uncompressed secp256k1
+    public key and returns the 33-byte compressed representation using
+    the cryptography library.
+
+    Args:
+        encoded: A secp256k1 public key in either compressed (33 bytes)
+            or uncompressed (65 bytes) SEC1 format.
+
+    Returns:
+        bytes: The 33-byte compressed public key.
+
+    Raises:
+        ValueError: If the input is not a valid SEC1 encoded point.
     """
     pub = ec.EllipticCurvePublicKey.from_encoded_point(SECP256K1_CURVE, encoded)
     compressed = pub.public_bytes(