AIKIDO-2026-961456

TL;DR

Several secret-key deserialization paths in miden-crypto read raw key bytes into a transient local buffer that was not wiped before that buffer was dropped. The ECDSA over secp256k1 secret-key reader left its buffer un-wiped on the early error return when byte validation rejected the input, while the Falcon512 and Poseidon2 AEAD secret-key readers never wiped their read buffers on any path, and decoded Falcon coefficient buffers were also left in place. As a result raw secret-key material could linger in freed process memory after deserialization, widening the window for recovery through memory inspection, swap, or core dumps. The fix adds a read_sensitive_array helper that returns the buffer wrapped in zeroize::Zeroizing so it is wiped on drop regardless of the exit path, migrates the affected readers to it, and wraps the decoded Falcon coefficient buffers in Zeroizing.