What is Passphrase?It Should Be Hard to GuessProtecting a Private KeyProtecting SSH keysPGP / GPG Private Key Protection
What is Passphrase?
A passphrase is similar to a password. However, a password generally refers to something used to authenticate or log into a system. A passphrase generally refers to a secret used to protect an encryption key. Commonly, an actual encryption key is derived from the passphrase and used to encrypt the protected resource.
It Should Be Hard to Guess
A good passphrase should have at least 15, preferably 20 characters and be difficult to guess. It should contain upper case letters, lower case letters, digits, and preferably at least one punctuation character. No part of it should be derivable from personal information about the user or his/her family.
The purpose of the passphrase is usually to encrypt the private key. This makes the key file by itself useless to an attacker. It is not uncommon for files to leak from backups or decommissioned hardware, and hackers commonly exfiltrate files from compromised systems.
To use an encrypted key, the passphrase is also needed. In a way, they are two separate factors of authentication.
Protecting SSH keys
SSH keys are used for authenticating users in information systems. The SSH keys themselves are private keys; the private key is further encrypted using a symmetric encryption key derived from a passphrase. The key derivation is done using a hash function.
Passphrases are commonly used for keys belonging to interactive users. Their use is strongly recommended to reduce risk of keys accidentally leaking from, e.g., backups or decommissioned disk drives.
In practice, however, most SSH keys are without a passphrase. There is no human to type in something for keys used for automation. The passphrase would have to be hard-coded in a script or stored in some kind of vault, where it can be retrieved by a script. An attacker with sufficient privileges can easily fool such a system. Thus, there would be relatively little extra protection for automation.
More than 90% of all SSH keys in most large enterprises are without a passphrase. However, this depends on the organization and its security policies.
SSH keys can be generated with tools such as ssh-keygen and PuTTYgen. These tools ask for a phrase to encrypt the generated key with.
PGP / GPG Private Key Protection
Private keys used in email encryption tools like PGP are also protected in a similar way. Such applications typically use private keys for digital signing and for decrypting email messages and files.
When it comes to passphrases, encryption, and key protection, I'm well-versed in the nuances and importance of securing sensitive data. Let's break down the concepts covered in the article:
Passphrase vs. Password:
A passphrase serves a similar function to a password but is primarily used to protect encryption keys rather than for system authentication. It's crucial to create robust passphrases that are longer (preferably 15-20 characters), include a mix of upper and lower case letters, digits, and even punctuation marks. Avoiding personal information in a passphrase is critical to prevent it from being guessed or hacked.
Protecting Private Keys:
Passphrases play a pivotal role in encrypting private keys, rendering the key file useless to attackers if obtained. It's common for files, including private keys, to leak from backups or decommissioned hardware. However, without the passphrase, the encrypted key remains inaccessible.
SSH Key Protection:
SSH keys, used for user authentication in information systems, involve encrypting the private key using a passphrase-derived symmetric encryption key. While passphrases add an extra layer of security, their implementation for automated processes is challenging. Most SSH keys used for automation lack passphrases due to the need for non-human interaction. However, this practice poses a risk, leaving keys vulnerable if accessed by an attacker with sufficient privileges.
Best Practices and Tools:
Proper SSH key management tools are recommended for secure access provisioning, regular key changes, and compliance. Tools like ssh-keygen and PuTTYgen facilitate the generation of SSH keys and prompt users to encrypt keys with a passphrase for added security.
PGP / GPG Key Protection:
Similar to SSH keys, private keys used in email encryption tools like PGP/GPG also rely on passphrase protection. These keys serve purposes like digital signing and decrypting email messages/files, emphasizing the need for strong passphrases to safeguard sensitive communications.
Understanding these concepts is pivotal for ensuring data security in various contexts where encryption keys play a crucial role in protecting sensitive information.
Your passphrase should be at least 4 words and 15 characters in length. For example, you might create a passphrase by using association techniques, such as scanning a room in your home and creating a passphrase that uses words to describe what you see (for example, “Closet lamp Bathroom Mug”).
The key to a good passphrase is randomness — the words you use to create a passphrase should not have an obvious connection between them. A good passphrase example is overripe-trekker-angular-envision-letter, while a passphrase like apple-peach-banana-cucumber would be much easier to crack.
A good passphrase is made up of four or more random words. Sentences don't make great passphrases as they can be easier to guess. For example, it is predictable to have spaces between words, a capital letter at the beginning and punctuation at the end.
Why does the NCSC recommend using 'three random words' as a way to create passwords? By using a password that's made up of three random words, you're creating a password that will be 'strong enough' to keep the criminals out, but easy enough for you to remember.
Yes, four words are fine given good hashing. 600,000 KDF iterations meet the standard though I personally prefer argon2 which is excellent at its default settings.
We recommend that you use passphrases, as they are longer and easier to remember than a password made up of random, mixed characters. A passphrase is a memorized phrase consisting of a sequence of mixed words with or without spaces. Your passphrase should be at least 4 words and 15 characters in length.
A strong password is: At least 12 characters long but 14 or more is better. A combination of uppercase letters, lowercase letters, numbers, and symbols. Not a word that can be found in a dictionary or the name of a person, character, product, or organization.
A passphrase is a sentencelike string of words used for authentication that is longer than a traditional password, easy to remember and difficult to crack. Typical passwords range, on average, from eight to 16 characters, while passphrases can reach up to 100 characters or more.
The system of creating passwords from three words randomly selected from a list, such as: 'blueberry train crash' or 'elephant artist buffalo', has been adopted by many organisations after extensive testing by NCSC showed it generates more robust passwords than traditional methods.
You can think of a passphrase as a short sentence that's at least 15 characters in length and consists of four or more words. By contrast, a password is usually shorter and more complicated. An example of a passphrase can be VirusOrMalwareMyDefenseIsRed.
Cyberattacks rely on human error and weak credentials in order to exploit users. Password length, rather than character variety, is the primary component of a password's strength, meaning passphrases are far more secure than passwords—even if they feature no special characters at all.
Your passphrase should be at least 4 words and 15 characters in length. For example, you might create a passphrase by using association techniques, such as scanning a room in your home and creating a passphrase that uses words to describe what you see (e.g. “Closet lamp Bathroom Mug”).
It is similar to a password but typically longer. A commonly used example of a passphrase is “correct horse battery staple”. The longer length and use of multiple words make passphrases more secure because they increase the number of possible combinations and make it harder for attackers to crack them.
When you're thinking of good password ideas, you need to keep the following criteria in mind: The password should be at least 12-15 characters long. It should use a combination of letters, numbers, and special characters. Spaces are also allowed.
A reminder of how a password was derived. In order to jog the user's memory, some login systems allow a hint to be entered, which is displayed each time the password is requested. For example, if the password contains the date of someone's birthday, one might enter the name of the person as the hint.
Introduction: My name is Merrill Bechtelar CPA, I am a clean, agreeable, glorious, magnificent, witty, enchanting, comfortable person who loves writing and wants to share my knowledge and understanding with you.
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