Question

Analyze the following computer password in terms of how secure it might be. Describe the criteria you use in determining its strengths and weaknesses.

born2ski4evr!

Answer 1

Short answer
- born2ski4evr! is easy for a human to remember but weaker than it looks. It mixes letters, digits and one symbol, but it’s phrase-like and uses predictable substitutions (2 = “to”, 4 = “for”, ! at the end). That makes it vulnerable to targeted/wordlist+rule attacks even though its raw length is decent (13 characters).

How I evaluated it (criteria)
- Length: 13 characters — better than many short passwords.
- Character classes: lowercase letters + digits + one punctuation mark. No uppercase letters.
- Predictability / dictionary content: contains recognizable words/phrases (born, ski, evr ≈ “ever”) and common leetspeak substitutions (2→to, 4→for). Phrase-like structure lowers entropy vs truly random characters.
- Common patterns: digits replacing short words and a symbol appended are extremely common patterns tried early by cracking tools.
- Entropy estimate & attack models: compared theoretical randomness (ideal case) to realistic attacker models (wordlists + substitution rules, and brute force).
- Contextual defenses: whether online limits, throttling, or slow hashing (bcrypt/scrypt/argon2) are used strongly affects real-world risk.

Entropy & cracking-time estimates (illustrative)
- If the 13 characters were uniformly random from the ~94 printable ASCII characters, entropy ≈ 13 * log2(94) ≈ 85 bits (very strong).
- Realistic case: because the password is a short phrase with substitutions, effective entropy is much lower. Example rough estimates:
- Attacker tries common words + leet rules: think of the pattern [word][digit][word][digit][punct]. If the attacker’s wordlist is 20,000–50,000 common words, entropy ≈ 3*log2(20k..50k) + 2*log2(10) + log2(3) ≈ ~45–55 bits.
- With specialized targeted cracking (wordlists tuned to hobbies/interests + substitution rules), such a password could appear early in guesses and be cracked in minutes-to-days on a powerful GPU cluster, or much faster in an online attack if no lockout exists.
- Online attacks: if the service blocks after a few bad attempts or uses rate limits, the password may be effectively safe from simple online guessing even if its entropy is modest.
- Offline attacks: if an attacker obtains a password hash and can run billions of guesses per second (typical for fast hashes), a ~45–55 bit effective entropy password can be cracked in hours-to-weeks depending on the attacker's hardware and exact entropy.

Strengths
- Memorable: easy for a human to remember.
- Decent length (13 chars) and includes at least one symbol and digits.

Weaknesses
- Predictable phrase and common leet substitutions lower real entropy.
- No uppercase letters.
- Common pattern (words + digit substitutions + symbol at end) is tried very early by cracking tools.
- If reused across sites, compromise of one site risks many accounts.

Recommendations to improve security
- Make it longer and more random: use either a longer passphrase of multiple unrelated words (Diceware-style 4–6 random words; 5 words ≈ 64 bits) or a password manager to generate a long random password (16+ characters, mixed classes).
- Avoid obvious substitutions and trailing symbols (e.g., don’t just append “!” or replace o→0, a→@, to/for→2/4). These are well-known and prioritized by cracking rules.
- Add true randomness to the phrase (insert an unexpected character, mix case in nonstandard positions, or add random digits in the middle).
- Use a unique password per account and enable multi-factor authentication.
- Ensure the service storing the password uses a slow salted hash (bcrypt, scrypt, Argon2) — this matters a lot if hashes are leaked.

Bottom line
born2ski4evr! is better than “password123” but still much weaker than an equally long random or properly constructed passphrase. For important accounts, replace it with a longer, less predictable passphrase or a generated password stored in a password manager and enable 2FA.