Multikey [repack] Access

❌ Complexity – key management, coordination overhead ❌ Larger signatures or additional rounds of communication ❌ Not standardized across all systems

Tagging systems, permissions lists, event participants, any “many-to-many” flattened into a document. multikey

If you had a specific software or protocol in mind (e.g., “multikey in Redis” or “multikey in AWS KMS”), let me know and I’ll narrow the review. ❌ Complexity – key management, coordination overhead ❌

❌ Standard library often missing (C++, Java, Python need custom or third-party) ❌ Memory overhead for multiple key mappings if done naively Each value in the array gets a separate

❌ Only one array field per compound index (MongoDB limitation) ❌ Index size can explode if arrays are huge (each element → one index entry) ❌ Performance degrades with very high cardinality arrays (many unique values per document)

Definition: A multikey index is an index on an array field in a document database (e.g., MongoDB). Each value in the array gets a separate index entry pointing to the same document.