Alphanumeric Characters and Alphanumeric Password Requirements

Topics

General Web, Data Privacy

TL;DR

Alphanumeric passwords combine letters, numbers, and special characters to dramatically increase the number of possible combinations a hacker must guess — making them far more secure than letter-only passwords. While no universal standard exists, strong alphanumeric passwords should be randomized, memorable, and have characters distributed throughout. Pairing them with two-factor authentication (2FA) provides an even stronger layer of protection for company data.

What is an alphanumeric password?

An alphanumeric password contains numbers, letters, and special characters (like an ampersand or hashtag). If you type in something like "password" to get into your system, you don't have an alphanumeric password. If you must tap in "p@ssw3rd$," you're following the rules we're discussing here. Almost 80 percent of us reset our passwordsopens in a new tab every 90 days due to simple forgetting. It's hard to think about making passwords even more complicated.

But this simple step could help protect a company's important assets and valuable data. When your company enables an alphanumeric password requirement, you're required to use a password with:

Letters. Anything from A to Z counts. You might be required to mix uppercase and lowercase versions.
Numbers. Anything from 0 to 10 works.
Special characters. Unusual symbols from dashes to dollar signs to parenthesis are included.

Why do more characters make a password harder to crack?

Dig into the mathopens in a new tab, and you'll understand why these steps are important.

Password Type	Length	Possible Combinations
Letters only	6 characters	26⁶
Letters, numbers & symbols	12 characters	72¹²

If your password contains just six letters, a hacker has 26⁶ guessing options. If your password contains 12 characters, including numbers and symbols, a hacker has 72¹² possibilities. It takes much, much longer to guess a password like this.

No standard alphanumeric rules exist. Some companies ask for more characters, and others need fewer.

How do you create a strong alphanumeric password?

If your company requires alphanumeric passwords, you must be creative to meet all of the rules and regulations.

For example, Harvard Universityopens in a new tab requires passwords that are:

Long. Passwords must contain at least ten characters, but students can use up to 100.
Varied. Students must use at least five unique characters.
Alphanumeric. Writers must include uppercase letters, lowercase versions, and special characters.

What should a password for a company like this look like?

An ideal password is:

Randomized. Don't use anything identifiableopens in a new tab, such as your name, address, or pet's name.
Easy to remember. Phrases are harder to forgetopens in a new tab than random strings of data.
Scrambled. Don't put numbers and characters in a pile at the beginning and end.

Let's imagine that we've just finished watching Grey's Anatomy. We haven't posted about the show anywhere on social media, and we don't work as a writer or an actor for the show. We could use this program to create an alphanumeric password for Harvard.

Here are a few alphanumeric password examples with this theory:

Gr@y&At0m
(r@yz&at0My
Gr8yz&atOMY!

When you come up with the perfect password, don't put it on a Post-It note on your monitor or share it with your best friend. Think of it as a closely guarded secret that can keep your company safe.

How does two-factor authentication strengthen password security?

And remember that hackers can crack even the strongest password. The best way to strengthen your password is to add in another factor, such as something you have in your possession. So-called "two-factor authentication (2FA)" is much harder for a hacker to manipulate and crack. We've written up a white paper about this practice, and we encourage you to check it out.

Frequently asked questions

What makes a password 'alphanumeric'?

An alphanumeric password includes a combination of letters (uppercase and lowercase), numbers (0–9), and special characters such as symbols, dashes, or dollar signs — as opposed to a simple letter-only password.

Why are alphanumeric passwords more secure than letter-only passwords?

The more character types a password includes, the more possible combinations a hacker must try. For example, a 6-character letter-only password has 26⁶ possible combinations, while a 12-character alphanumeric password has 72¹² — an astronomically larger number that takes far longer to crack.

Is there a universal standard for alphanumeric password requirements?

No universal standard exists. Requirements vary by organization — for instance, Harvard University requires at least ten characters, five unique characters, and a mix of uppercase, lowercase, and special characters, while other companies may set different rules.

What should I avoid when creating an alphanumeric password?

Avoid using anything personally identifiable, such as your name, address, or pet's name. Also avoid clustering all numbers and special characters at the beginning or end of the password — distributing them throughout makes the password harder to guess.

How can I make a strong alphanumeric password that's also easy to remember?

Using a phrase or reference that is meaningful to you but not publicly associated with you (such as a TV show you watch privately) can help. Scramble the letters and substitute numbers or symbols for certain characters to meet complexity requirements while keeping it memorable.

Is an alphanumeric password enough to fully protect my account?

Not entirely. Even the strongest alphanumeric password can potentially be cracked. Adding a second factor — such as something you physically possess — through two-factor authentication (2FA) significantly increases account security beyond what a password alone can provide.