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Password

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A password, also known as a passcode, is a piece of secret data used to confirm a user's identity. It is typically a string of characters, such as letters, digits, or symbols. In technical terms, the person holding the secret is called the claimant. The party checking the identity is known as the verifier. When a claimant uses an authentication protocol to show they know the secret, the verifier can infer who they are.

Mediawiki 1.25 sign in form
Mediawiki 1.25 sign in form

The mechanism of authentication involves a specific sequence of steps. First, the verifier requests the secret through an established protocol. The claimant then provides the sequence of characters they have memorized. The verifier compares this input to the stored data. If the characters match, access is granted. To protect privacy, many systems hide the characters as they are typed. This prevents bystanders from seeing the secret through a method called shoulder surfing.

There are different types of secret strings used for security. If the characters are strictly numeric, the secret is called a personal identification number, or PIN. If the secret is a long sequence of words separated by spaces, it is called a passphrase. While similar to a password, a passphrase is generally longer to provide added security. A password does not actually have to be a real word. In fact, using a non-word can make it much harder for someone to guess.

Humans have used passwords for security since ancient times. The Roman military used a system of watchwords to secure their camps. According to the historian Polybius, a man would receive a wooden tablet with a word inscribed on it. He would pass the tablet and the word to the next commander in a chain. Once the tablet returned to the original tribune, the leader knew everyone had received the word. During the Battle of Normandy, U.S. paratroopers used a challenge and response system. A soldier would say "flash," and the correct response was "thunder." They even used a device called a "cricket" that made metallic clicks to identify one another.

In the digital age, passwords became essential for computer security. The first system to use password logins was the Compatible Time-Sharing System (CTSS) at MIT in 1961. In the early 1970s, Robert Morris developed a way to store passwords in a hashed form. This was part of the Unix operating system and appeared in the 6th Edition in 1974. His algorithm used a 12-bit salt and a modified DES algorithm to reduce the risk of dictionary attacks. Today, people use passwords for everything from mobile phones to automated teller machines (ATMs).

Choosing a secure password is a difficult balance for many users. If a password is easy to remember, it might be easy to guess. If it is too complex, users might write it down or reuse it across many accounts. A survey suggested the average user manages around 100 different passwords. Google released a list in 2013 of insecure passwords, such as pet names or birthdays. Using a single dictionary word is also considered weak. Instead, experts suggest using long phrases or combining unrelated words with special characters.

Security systems also use technical methods to stop attackers from guessing. One method is throttling, which imposes a time-out after a few failed attempts. Another method is to disable an account after a specific number of bad guesses. Some systems use key stretching to make the process of checking a password much slower. This makes it harder for an attacker to use high-speed hardware to guess many passwords at once.

Cafe wifi sign in Christchurch, New Zealand (52385843342)
Cafe wifi sign in Christchurch, New Zealand (52385843342)

Passwords are connected to broader fields of cybersecurity and identity management. Because memorizing 100 passwords is impractical, many people use password managers. These tools allow a user to remember only one master password. Others use single sign-on systems to manage access to many different services. As technology evolves, the way we protect our digital identities continues to change to meet new threats.

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