Full key-recovery attack on SpoC-128

The problem asks whether the unmodified SpoC-128 authenticated-encryption scheme has a practical attack recovering its complete secret key. The retrieved record contains no claimed attack against that exact target.

Known results

• A 2020 cryptanalysis gives reduced-round attacks, including forgery and message-recovery attacks against $9$-round SpoC-64.
• The same work gives a full-round time-memory-tradeoff key-recovery attack for SpoC-64, not SpoC-128.
• NIST’s 2020 assessment discusses reduced-round, related-key, and related-nonce analyses, and reports that they do not threaten SpoC-128’s security claims; the full scheme has $18$ rounds.

Current status (as of September 2026): No practical full-strength key-recovery attack on unmodified SpoC-128 is publicly reported; only reduced or modified settings have documented attacks.