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In Security Last updated: August 31, 2023
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Increasing digital refinements have increased cyber crimes online. Cyber attacks like Dictionary Attacks are becoming threats to one’s identity, organization, and data.

This article delves into what dictionary attacks are, how they differ from other attacks, and how to avoid them.

What are Dictionary Attacks?

Dictionary attacks are a way to detect a cipher’s encryption key using a confined subset of entries from a predefined list called a ‘dictionary’ to access a system or an account. Hence, this attack is called a dictionary attack. These attacks usually hack email accounts, Wi-Fi passwords, weak encrypted keys, and online banking accounts.


This dictionary consists of thousands and millions of entries from previous security breaches’ databases. The dictionary attacks are usually successful because many people use common and short passwords that are easy to predict as per the past breach data, like appending a digit, punctuation characters, personal identification numbers, similar-looking characters, etc.

Dictionary attacks, also known as a type of brute force attack, can be done online and offline. In the online dictionary attack, the hacker exploits commonly used passwords created by a system or past breach data research. 

The online attack must be quick. If the attack takes too long to proceed, it may get noticed by the system owner. In an offline attack, the hacker can try the list of passwords from the dictionary multiple times without getting banned.

Effects of Dictionary Attacks

Dictionary attacks are as detrimental as any other cyber attack. If the password guess is accurate, the hacker can easily access the entire system or account and potentially steal sensitive data. This unauthorized access can lead to financial loss, data breaches, and identity theft.

This attack can generate several losses for an organization as the hacker gets more power to access other accounts of important applications that are saved on the system. The dictionary attack can lead to reputational damage and loss of trust from the stakeholders and clients due to their inability to secure the data.

Cyber attackers can also access the personal data of the system’s owner, which can be harmful. Thus, one dictionary attack leads to more dictionary attacks and data breaches. Due to increased security measures and economic losses, dictionary attacks also affect the company’s budget.

Organizations suffer a significant loss if the attackers control their systems entirely. This attack may lead to financial setbacks, downtime, loss of productivity, and legal action due to data breaches.

How Does Dictionary Attack Work?

Let’s try to understand how the dictionary attack happens.

Step 1: Cyber attackers perform dictionary attacks in different ways. Some only used the commonly used optimized list of passwords, while others checked the entire dictionary.

Cyber hackers collect commonly used passwords from various sources, such as past breached databases, leaked passwords, and pre-assumed libraries of phrases. For example, a person can use a common password like pass1234 or p1234. 

The hackers also find entries based on lifestyle and demographics in the dictionary from the past breached data. For example, many young footballer enthusiasts used passwords like ‘messi123’ or ‘foot1234ball’. This dictionary may have thousands and millions of entries.

A man sitting at a desk with two monitors in front of him.

Step 2: After creating the dictionary of passwords, the hackers try to find the target system they want to breach. These target systems include email, social media, website user accounts, or applications.

Step 3: When the dictionary of passwords and the target system is ready, the attackers try to match each password with the target system’s user ID.

Step 4: Cyber attackers use automated and robust software or computing setups for such attacks. If the password doesn’t match, this procedure continues for every password until the correct password matches the user ID.

Dictionary attacks are usually successful when the passwords are weak and easy to guess. Moreover, hackers can access several other accounts with similar passwords within the same system. If the hacker is an intelligent player, they will complete this process in very little time.

Dictionary Attack vs. Brute Force Attacks

The dictionary attack is similar to a brute-force attack. In the dictionary attack, the attacker guesses every possible word they can use from the dictionary. These attacks are fast, as the hacker doesn’t guess a password’s every possible character.

The brute-force attack tries every possible combination of characters from the password dictionary. Such attacks are usually slow and computationally intensive.

Dictionary Attack vs. Password Spraying

The password spraying is part of a dictionary attack. The only difference in this attack is that it uses the same Password for all the user IDs. In this way, the hacker will try to use multiple accounts with a limited number of passwords. This attack’s success rate is lower than the dictionary and brute-force attacks. This technique can be effective for those accounts with weak passwords.

Dictionary Attack vs. Rainbow Table Attack

The rainbow table attack is slightly different from the dictionary attack. The cyber hacker compares the hash value of the target password with the hash values stored in the rainbow table. According to this hash value, the hacker’s team tries to match and retrieve the password. In the dictionary attack, the hacker uses all the strings in the dictionary to match the password.

These attacks are speedy as they look for hash values in a pre-computed table instead of using all the passwords from the predefined list. Salting passwords, i.e., adding random data to each password before hashing, can reduce the probability of a Rainbow table attack.

Some Real-life Examples of Dictionary Attack

LinkedIn Breach

The LinkedIn website suffered from a severe data breach in the year 2012. The website suffered from a dictionary attack that exposed 160 million user credentials due to unsalted SHA-1 hashes for password storage and weak security practices.

The Ashley Madison Hack

A dating website, Ashley Madison suffered from a controversial data breach in 2015. In this dictionary attack, the attackers hacked the hashed passwords, personal information, and payment details of the people using this site. This breach occurred due to feeble security measures.

The Dropbox Breach

Dropbox’s cloud storage also suffered a significant dictionary attack, hacking 68 million hashed passwords and email addresses. This dictionary attack occurred due to weak passwords.

The Adobe’s Hack

The very famous Adobe also suffered from a controversial dictionary attack in 2013. In this breach, 38 million users’ sensitive data was exposed. This data included encrypted passwords as well as credit card information. This dictionary attack occurred due to weak encryption methods.

A man using a laptop with the word security on it.

How to Mitigate Dictionary Attacks

The real-life examples mentioned above remind us that a secured network and strong encryption are crucial to mitigating dictionary attacks.

  • Two-Factor Authentication (2FA): The Two-factor authentication method is the best way to secure your account from malicious attacks. In this method, when the user signs into the account, the website sends an OTP via SMS to the account holder’s phone number for the second time for account verification. You can only access the account if you enter the correct OTP number. Two-factor authentication is also the safest way to secure your social media platforms.
  • Strong Passwords: Opt for unique and complex passwords. Integrate a combination of upper and lower-case letters with special characters. You can also avoid using guessable passwords with repeated numbers, number series, or your name in your password.
  • Password Managers: You can employ password managers to help you generate unique and strong passwords for each account. Password managers reduce the burden of remembering your passwords for various accounts.
  • Update Regularly: Keep your apps, software, and operating system updated regularly. Cyber attackers often exploit known vulnerabilities in outdated software.
  • Account Lockout Policy: The account lockout temporarily locks accounts after a specific number of failed signing attempts. This policy secures the account and prevents cyber attackers from using automated software for dictionary attacks. 
  • Use Captcha: Using a captcha on websites while accessing the account helps distinguish the activity of automated bots and humans.
  • Web Application Firewalls (WAF): Deploying web application firewalls can block malicious traffic to your system. WAF also prevents dictionary attacks.
  • Network Segmentation: Limit your network access from sensitive sites by segmenting it. This procedure protects the system from malicious attacks. 
  • Security Audits and Penetration Techniques: Regularly conducting penetration techniques and security audits can resolve network and software vulnerabilities and weaknesses.
  • Implement Behavioural Analytics Tools: We can detect unusual login activities if we implement behavioral analytics tools. 
  • Intrusion Detection and Prevention Systems (IDPS): Many IDPS tools help to detect network traffic and suspicious login attempts and patterns.
  • Regular Password Change: If we regularly change passwords, we reduce the risk of cyber attacks.
  • Adopting New Technologies: Many companies are introducing new software and technologies like passwordless or OTP login, open authorization (OAuth), or simply mailing the link to log in for safe access.
  • Google Password Manager securely saves all the passwords of different accounts. It also gives strong password ideas. For example, Google Password Manager gives ideas to save unique passwords for your accounts. For the website, the Google password manager suggests a strong-length password with a combination of upper and lower case letters, special characters, and digits like ‘6exRa$c57GUjas2’. These password-generation ideas protect the account from dictionary attacks. 
  • 1Password offers strong security measures like securing storage for passwords and other sensitive data like credit card information.
  • LastPass is a powerful password manager. This website offers password generation, secure storage, and device synchronization services. It supports multi-factor authentication.
  • Dashlane offers password security storage, password generation, and digital wallet storage. It also offers to update the password regularly.
  • Keeper is an encryption and security software that offers password management, encrypted messaging, dark web monitoring, and digital file storage. 

What to do if you Become a Victim of a Dictionary Attack

  • Identify the beach account and monitor the suspicious activities. Check all your online accounts, like email, social media, and other platforms.
  • Change your password immediately and add multi-factor or two-factor authentication for extra security.
  • Report the malicious activity to customer care immediately. Also, inquire about any additional security measures.
  • Stay vigilant, monitor your accounts, and update your applications and software regularly.


As technology continues to evolve, so do the tactics of cyber attackers to crack the code. Thus, by being more aware of our online activities and implementing best practices, we can readily thwart dictionary attacks and protect our digital assets. To learn more, here are some cybersecurity basics for beginners.

  • Anuja Shende
    Anuja has been in SEO field for the past 5.5 years and writes SEO-friendly content. She has completed her degree in computer engineering. She loves to sing, play guitar and ukulele, and read spiritual and non-fictional books.
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