This vulnerability occurs when a software implementation skips a critical step in a cryptographic process, resulting in security that is significantly weaker than the intended algorithm provides.
Cryptographic algorithms are designed as a sequence of specific, interdependent steps. Each step serves a purpose, such as ensuring randomness, preventing pattern analysis, or binding data together securely. When a developer omits one of these steps—whether during key generation, encryption, decryption, or integrity verification—the entire cryptographic operation becomes fragile. The resulting system may appear to function normally but can be easily broken by attackers using well-known techniques, completely undermining the promised security. This flaw often stems from using incomplete code samples, misunderstanding algorithm specifications, or attempting to 'optimize' performance by removing so-called 'unnecessary' operations. To prevent it, developers should rely on reputable, high-level cryptographic libraries rather than implementing algorithms from scratch. Always follow the official algorithm specification or RFC meticulously, and use established test vectors to verify that every required step is correctly executed in the proper order.
Impact: Bypass Protection Mechanism
Impact: Read Application DataModify Application Data
Impact: Hide Activities
logic [511:0] bigData; ...
hmac hmac(
verilog
.message_i(bigData),** .hash_o(hash), .ready_o(ready), .hash_valid_o(hashValid)