A new study by Specops Software explores the resilience of SHA256, a commonly used cryptographic hashing algorithm, against modern password-cracking techniques. The findings emphasize the algorithm’s effectiveness in protecting data, especially when combined with strong, complex passwords. However, the research also highlights vulnerabilities when using short or simple passwords, even with this robust technology.
SHA256, renowned for its collision resistance and speed, is widely implemented in areas like blockchain, digital certificates, and password storage. However, its simplicity—originally a strength—has become a potential liability in the era of advanced GPU technology. Using an Nvidia RTX 4090, researchers demonstrated how weak passwords, such as eight-character combinations, could be cracked in seconds. This alarming finding underscores the limitations of SHA256 when used without additional security layers like salts or password policies.
The study stresses the importance of password length and complexity as critical deterrents to brute-force attacks. Passwords exceeding 14 characters, combined with upper and lowercase letters, numbers, and symbols, exponentially increase cracking difficulty. Furthermore, security mechanisms like salting (adding unique random data to hashed passwords) or key stretching (intentionally slowing hash generation) can significantly enhance SHA256’s defenses.
Beyond algorithmic capabilities, the research brings attention to human factors. Poor password hygiene—such as reusing passwords across multiple accounts—remains a pervasive risk. Highly secure hashing mechanisms like SHA256 cannot compensate for weak user practices. Organizations are urged to enforce stringent password policies, encourage multi-factor authentication, and educate users on password security.
Specops Software’s research highlights a pressing need for a layered approach to digital security. While SHA256 remains a vital tool in safeguarding sensitive data, its limitations in password-hashing applications should prompt developers and security teams to explore complementary strategies.
Darren James, Senior Product Manager at Specops Software, said this about the findings: “It’s a cybersecurity blunder to store passwords in plaintext, as anyone who gains unauthorized access to the database could simply read them. Hashing algorithms solve this problem to an extent, although it is technically possible to crack hashed passwords through brute-force guessing via powerful hardware and sophisticated software.”
“Even with dictionary lists and other aids, hackers still often only have the chance to crack the shortest, simplest passwords. SHA256 is a relatively modern hashing algorithm and as our research shows, it can easily put the ‘time to crack’ up to thousands (or even millions) of years for strong passwords. However, it’s important for organizations to remember that hashing algorithms can be rendered irrelevant due to end user mistakes. For example, a password becoming compromised through password reuse.”
As cyber threats grow increasingly sophisticated, organizations and individuals alike must take responsibility for staying ahead. Strengthening password protocols and leveraging advanced security technologies are essential to addressing evolving risks.
