BIP 158: Specify endianness of block hash to k conversion.

Author: jimpo

bip-0158.mediawiki

@@ -280,7 +280,7 @@ following items for each transaction in a block:
 * The scriptPubKey of each output, aside from all <code>OP_RETURN</code> output
   scripts.
 
-Any "nil" items MUST NOT be included into the final set of filter elements. 
+Any "nil" items MUST NOT be included into the final set of filter elements.
 
 We exclude all <code>OP_RETURN</code> outputs in order to allow filters to
 easily be committed to in the future via a soft-fork. A likely area for future
@@ -303,11 +303,12 @@ setting <code>M=1.497137 * 2^P</code> is close to optimal
 
 Empirical analysis also shows that was chosen as these parameters minimize the
 bandwidth utilized, considering both the expected number of blocks downloaded
-due to false positives and the size of the filters themselves. 
+due to false positives and the size of the filters themselves.
 
-The parameter <code>k</code> MUST be set to the first 16 bytes of the hash of
-the block for which the filter is constructed. This ensures the key is
-deterministic while still varying from block to block.
+The parameter <code>k</code> MUST be set to the first 16 bytes of the hash
+(in standard little-endian representation) of the block for which the filter is
+constructed. This ensures the key is deterministic while still varying from
+block to block.
 
 Since the value <code>N</code> is required to decode a GCS, a serialized GCS
 includes it as a prefix, written as a <code>CompactSize</code>. Thus, the