{"id":3594,"date":"2026-07-14T12:32:16","date_gmt":"2026-07-14T10:32:16","guid":{"rendered":"https:\/\/science-x.net\/?p=3594"},"modified":"2026-07-14T12:32:17","modified_gmt":"2026-07-14T10:32:17","slug":"how-passwords-are-stored-and-why-websites-fortunately-do-not-know-them","status":"publish","type":"post","link":"https:\/\/science-x.net\/?p=3594","title":{"rendered":"How Passwords Are Stored and Why Websites Fortunately Do Not Know Them"},"content":{"rendered":"\n

Passwords feel simple from the user\u2019s side. You type a secret phrase, click \u201cLog in,\u201d and the website either lets you in or rejects you. But behind that simple moment is one of the most important ideas in cybersecurity: a good website should not actually know your password<\/strong>.<\/p>\n\n\n\n

That may sound strange. If a website does not know your password, how can it check whether you typed the right one? The answer is password hashing. Instead of storing the password itself, secure systems store a transformed version called a hash<\/strong>. When you log in, the website hashes the password you entered and compares the result with the stored hash.<\/p>\n\n\n\n

This design protects users when databases are stolen. A hacker who breaks into a poorly protected system with plain-text passwords can immediately read everyone\u2019s credentials. A hacker who steals properly salted and hashed passwords gets a much harder problem: they must guess the original passwords one by one.<\/p>\n\n\n\n

Password storage is not about remembering your password. It is about verifying it without keeping it in a readable form.<\/strong><\/p>\n\n\n\n

Plain Text Passwords: The Worst Possible Storage<\/h3>\n\n\n\n

The most dangerous way to store passwords is plain text.<\/p>\n\n\n\n

That means the database contains passwords exactly as users typed them:<\/p>\n\n\n\n

    \n
  • summer2026<\/code><\/li>\n\n\n\n
  • MyDogCharlie!<\/code><\/li>\n\n\n\n
  • qwerty123<\/code><\/li>\n\n\n\n
  • correct horse battery staple<\/code><\/li>\n<\/ul>\n\n\n\n

    If such a database leaks, every password is immediately exposed.<\/p>\n\n\n\n

    This is disastrous because many people reuse passwords across websites. One leaked password can unlock email, social media, banking, cloud storage, or work accounts.<\/p>\n\n\n\n

    Security organizations strongly warn against plain-text password storage. OWASP states that passwords should never be stored in plain text and should instead be protected with strong, slow hashing algorithms such as Argon2id, bcrypt, or PBKDF2.<\/p>\n\n\n\n

    If a website can email you your current password, that is a serious red flag.<\/strong><\/p>\n\n\n\n

    What Is Password Hashing?<\/h3>\n\n\n\n

    A hash function<\/strong> takes input data and produces a fixed-looking output.<\/p>\n\n\n\n

    For passwords, the important idea is that the transformation should be one-way.<\/p>\n\n\n\n

    For example, a password goes in:<\/p>\n\n\n\n

    BlueRiverCoffee42!<\/code><\/p>\n\n\n\n

    And a hash comes out:<\/p>\n\n\n\n

    a long string of letters, numbers, and symbols<\/code><\/p>\n\n\n\n

    The website stores the hash, not the password.<\/p>\n\n\n\n

    When you log in, the system does this:<\/p>\n\n\n\n

      \n
    1. You enter your password.<\/li>\n\n\n\n
    2. The website hashes what you typed.<\/li>\n\n\n\n
    3. It compares the new hash with the stored hash.<\/li>\n\n\n\n
    4. If they match, access is granted.<\/li>\n<\/ol>\n\n\n\n

      The website does not need to decrypt the password because there is no password to decrypt<\/strong>.<\/p>\n\n\n\n

      A properly designed hash is not meant to be reversed.<\/p>\n\n\n\n

      Hashing Is Not Encryption<\/h3>\n\n\n\n

      Many people confuse hashing and encryption.<\/p>\n\n\n\n

      Encryption is reversible if you have the key.<\/p>\n\n\n\n

      For example, a secure messaging app may encrypt a message and later decrypt it for the intended recipient.<\/p>\n\n\n\n

      Hashing is different.<\/p>\n\n\n\n

      A password hash should be one-way. The system should verify the password without being able to recover the original password.<\/p>\n\n\n\n

      This distinction matters because passwords should generally not be stored with reversible encryption.<\/p>\n\n\n\n

      OWASP\u2019s cryptographic storage guidance notes that passwords should not be stored using reversible encryption.<\/p>\n\n\n\n

      Encryption hides information temporarily. Password hashing transforms it for verification.<\/strong><\/p>\n\n\n\n

      Why Websites Add Salt<\/h3>\n\n\n\n

      A salt<\/strong> is a random value added to a password before hashing.<\/p>\n\n\n\n

      Each user should have a unique salt.<\/p>\n\n\n\n

      Without salts, two users with the same password would have the same hash. That makes attacks easier.<\/p>\n\n\n\n

      With salts, even if two users choose the same password, their stored hashes look different.<\/p>\n\n\n\n

      Salts also defend against rainbow tables<\/strong>, which are huge precomputed lists of common password hashes.<\/p>\n\n\n\n

      NIST states that password verifiers should store passwords in a form resistant to offline attacks and that passwords should be salted and hashed using a suitable password hashing scheme.<\/p>\n\n\n\n

      A salt does not need to be secret. Its job is to make every password hash unique.<\/strong><\/p>\n\n\n\n

      Why Fast Hashes Are Bad for Passwords<\/h3>\n\n\n\n

      Fast hashing algorithms such as SHA-256 are useful in many areas of computing, but they are not ideal for password storage by themselves.<\/p>\n\n\n\n

      Why?<\/p>\n\n\n\n

      Because attackers are fast too.<\/p>\n\n\n\n

      If hackers steal a password database, they can try billions of guesses using powerful graphics cards or specialized hardware. A fast hash lets them test guesses extremely quickly.<\/p>\n\n\n\n

      Password hashing should be deliberately slow and expensive.<\/p>\n\n\n\n

      Good password hashing algorithms include:<\/p>\n\n\n\n

        \n
      • Argon2id<\/li>\n\n\n\n
      • bcrypt<\/li>\n\n\n\n
      • scrypt<\/li>\n\n\n\n
      • PBKDF2 with strong settings<\/li>\n<\/ul>\n\n\n\n

        OWASP warns that fast hashing algorithms such as SHA-256 are not suitable for password storage because attackers can perform huge numbers of guesses quickly.<\/p>\n\n\n\n

        For password storage, slowness is a security feature.<\/strong><\/p>\n\n\n\n

        What Makes Argon2id, bcrypt, and PBKDF2 Different?<\/h3>\n\n\n\n

        Modern password hashing algorithms are designed to make cracking expensive.<\/p>\n\n\n\n

        bcrypt<\/strong> has been used for many years and remains common in legacy and current systems.<\/p>\n\n\n\n

        PBKDF2<\/strong> is widely standardized and still used, especially in environments that require certain compliance rules.<\/p>\n\n\n\n

        Argon2id<\/strong> is often recommended for modern systems because it is memory-hard, meaning it forces attackers to use significant memory as well as computing power.<\/p>\n\n\n\n

        OWASP recommends strong adaptive and salted hashing functions with a work factor, including Argon2, yescrypt, scrypt, or PBKDF2-HMAC-SHA-512, and directs legacy bcrypt users to its password storage guidance.<\/p>\n\n\n\n

        The point is not only the algorithm name. Configuration matters too.<\/p>\n\n\n\n

        A weakly configured secure algorithm can still be easier to attack than it should be.<\/p>\n\n\n\n

        What Happens During a Data Breach?<\/h3>\n\n\n\n

        If a website stores passwords properly, a breach does not automatically reveal passwords.<\/p>\n\n\n\n

        Attackers may steal:<\/p>\n\n\n\n

          \n
        • Email addresses<\/li>\n\n\n\n
        • Usernames<\/li>\n\n\n\n
        • Password hashes<\/li>\n\n\n\n
        • Salts<\/li>\n\n\n\n
        • Profile data<\/li>\n\n\n\n
        • Session tokens<\/li>\n\n\n\n
        • Other account information<\/li>\n<\/ul>\n\n\n\n

          The password hashes are still dangerous, but they are not immediately readable.<\/p>\n\n\n\n

          Attackers must guess passwords, hash each guess with the correct salt, and compare the result.<\/p>\n\n\n\n

          Weak passwords may still be cracked quickly.<\/p>\n\n\n\n

          Strong unique passwords are much harder.<\/p>\n\n\n\n

          Hashing buys time and protection, but weak passwords can still lose.<\/strong><\/p>\n\n\n\n

          Why Strong Passwords Still Matter<\/h3>\n\n\n\n

          Even the best storage system cannot fully protect a terrible password.<\/p>\n\n\n\n

          If your password is:<\/p>\n\n\n\n

          123456<\/code><\/p>\n\n\n\n

          or<\/p>\n\n\n\n

          password<\/code><\/p>\n\n\n\n

          or<\/p>\n\n\n\n

          iloveyou<\/code><\/p>\n\n\n\n

          attackers will guess it early.<\/p>\n\n\n\n

          Good password storage slows attackers down, but it does not make weak passwords magically safe.<\/p>\n\n\n\n

          A strong password should be:<\/p>\n\n\n\n

            \n
          • Long<\/li>\n\n\n\n
          • Unique<\/li>\n\n\n\n
          • Hard to guess<\/li>\n\n\n\n
          • Not reused<\/li>\n\n\n\n
          • Stored in a password manager if needed<\/li>\n<\/ul>\n\n\n\n

            A long passphrase can be easier to remember than a short complicated password.<\/p>\n\n\n\n

            For example, a phrase made from several unrelated words is often stronger than a short password with predictable substitutions.<\/p>\n\n\n\n

            The best password is one you do not reuse anywhere else.<\/strong><\/p>\n\n\n\n

            Why Password Managers Are So Useful<\/h3>\n\n\n\n

            Password managers solve one of the biggest human problems in security: memory.<\/p>\n\n\n\n

            People cannot realistically memorize strong unique passwords for every account.<\/p>\n\n\n\n

            A password manager can generate and store passwords such as:<\/p>\n\n\n\n

            T7v!q2L#p9Zx@41mR<\/code><\/p>\n\n\n\n

            You do not need to remember each one.<\/p>\n\n\n\n

            You only need to protect the password manager with one strong master password and, ideally, multi-factor authentication.<\/p>\n\n\n\n

            This prevents password reuse, which is one of the most common reasons one data breach spreads into many account takeovers.<\/p>\n\n\n\n

            Multi-Factor Authentication Adds Another Lock<\/h3>\n\n\n\n

            Even strong password storage does not stop every attack.<\/p>\n\n\n\n

            A user can still be tricked by phishing.<\/p>\n\n\n\n

            A device can be infected with malware.<\/p>\n\n\n\n

            A password can be reused from another breach.<\/p>\n\n\n\n

            That is why multi-factor authentication<\/strong>, or MFA, is so important.<\/p>\n\n\n\n

            MFA requires something beyond the password, such as:<\/p>\n\n\n\n

              \n
            • An authenticator app code<\/li>\n\n\n\n
            • A hardware security key<\/li>\n\n\n\n
            • A biometric check<\/li>\n\n\n\n
            • A trusted device confirmation<\/li>\n<\/ul>\n\n\n\n

              A password proves what you know. MFA adds proof from something you have or something you are.<\/strong><\/p>\n\n\n\n

              Expert Perspective<\/h3>\n\n\n\n

              The expert consensus from organizations such as OWASP<\/strong> and NIST<\/strong> is clear: websites should never store readable passwords. They should use salted, slow, suitable password hashing schemes designed to resist offline attacks. NIST specifically states that password verifiers should store passwords in a form resistant to offline attacks, using salts, a cost factor, and a suitable password hashing scheme.<\/p>\n\n\n\n

              This is why responsible websites cannot tell you your old password. They can only let you reset it.<\/p>\n\n\n\n

              A password reset link is normal. A website revealing your current password is not.<\/strong><\/p>\n\n\n\n

              Why Websites \u201cNot Knowing\u201d Your Password Is Good News<\/h3>\n\n\n\n

              When a website says \u201cincorrect password,\u201d it does not need to know the password you originally chose.<\/p>\n\n\n\n

              It only needs to know whether the hash of what you typed matches the hash stored earlier.<\/p>\n\n\n\n

              That is the beauty of modern password security.<\/p>\n\n\n\n

              The website can verify your identity without keeping your secret in readable form.<\/p>\n\n\n\n

              This protects both users and companies.<\/p>\n\n\n\n

              If a breach happens, proper hashing can prevent immediate mass exposure.<\/p>\n\n\n\n

              If users also choose unique strong passwords and enable MFA, the damage becomes much harder for attackers to exploit.<\/p>\n\n\n\n

              The safest password is one the website can verify but cannot read.<\/strong><\/p>\n\n\n\n

              Interesting Facts<\/h2>\n\n\n\n
                \n
              • A secure website should not be able to show you your current password.<\/li>\n\n\n\n
              • Password hashes are one-way transformations used for verification.<\/li>\n\n\n\n
              • Salts make identical passwords produce different stored hashes.<\/li>\n\n\n\n
              • Fast hashes like plain SHA-256 are not recommended for password storage by themselves.<\/li>\n\n\n\n
              • Argon2id, bcrypt, scrypt, and PBKDF2 are common password hashing approaches.<\/li>\n\n\n\n
              • A password reset is safer than sending a user their old password.<\/li>\n\n\n\n
              • Password managers make it practical to use unique passwords for every account.<\/li>\n<\/ul>\n\n\n\n

                Glossary<\/h2>\n\n\n\n
                  \n
                • Password Hash<\/strong> \u2014 A one-way transformed version of a password used for verification.<\/li>\n\n\n\n
                • Plain Text<\/strong> \u2014 Readable, unprotected data stored exactly as entered.<\/li>\n\n\n\n
                • Salt<\/strong> \u2014 A random value added to a password before hashing to make each hash unique.<\/li>\n\n\n\n
                • Rainbow Table<\/strong> \u2014 A precomputed database of hashes used to crack passwords faster.<\/li>\n\n\n\n
                • Argon2id<\/strong> \u2014 A modern password hashing algorithm designed to resist powerful cracking attacks.<\/li>\n\n\n\n
                • bcrypt<\/strong> \u2014 A widely used password hashing algorithm designed to be slower and harder to brute-force than ordinary hashes.<\/li>\n\n\n\n
                • PBKDF2<\/strong> \u2014 A password-based key derivation function often used for password hashing in standardized environments.<\/li>\n\n\n\n
                • Multi-Factor Authentication<\/strong> \u2014 A login method requiring an additional proof beyond the password.<\/li>\n<\/ul>\n","protected":false},"excerpt":{"rendered":"

                  Passwords feel simple from the user\u2019s side. You type a secret phrase, click \u201cLog in,\u201d and the website either lets you in or rejects you. But behind that simple moment…<\/p>\n","protected":false},"author":2,"featured_media":3595,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_sitemap_exclude":false,"_sitemap_priority":"","_sitemap_frequency":"","footnotes":""},"categories":[65,1,57],"tags":[],"_links":{"self":[{"href":"https:\/\/science-x.net\/index.php?rest_route=\/wp\/v2\/posts\/3594"}],"collection":[{"href":"https:\/\/science-x.net\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/science-x.net\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/science-x.net\/index.php?rest_route=\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/science-x.net\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=3594"}],"version-history":[{"count":1,"href":"https:\/\/science-x.net\/index.php?rest_route=\/wp\/v2\/posts\/3594\/revisions"}],"predecessor-version":[{"id":3596,"href":"https:\/\/science-x.net\/index.php?rest_route=\/wp\/v2\/posts\/3594\/revisions\/3596"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/science-x.net\/index.php?rest_route=\/wp\/v2\/media\/3595"}],"wp:attachment":[{"href":"https:\/\/science-x.net\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=3594"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/science-x.net\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=3594"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/science-x.net\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=3594"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}