Who can you trust?

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You close the door and authenticate

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1. Something you know

2. Something you have

3. Something you are

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Step 1

Passwords

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Passwords are keys

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Each site or service has a lock

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When you get
more locks...

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...you need more keys

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And it never ends...

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...ever...

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How many passwords have you memorised?

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How many times have you used the same password?

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List of the 18 most common passwords in 2019 according to the NCSC
https://www.ncsc.gov.uk/news/most-hacked-passwords-revealed-as-uk-cyber-survey-exposes-gaps-in-online-security

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Humans vs Machines

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Speed of calculation

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Correctness of action

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Capacity of memory

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Brute-force

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1. 'a', 'b', 'c'...
2. 'aa', 'ab', 'ac'...
3. 'aaaaaaaa', 'aaaaaaab'...

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1. Try all words alone
2. Try all combinations of 2 words
3. Try all combinations of N words

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1. Try the most common passwords
2. Try the most common words
3. Try the most common variants

What makes a
good password?

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1. How many different symbols? :: n
2. How many symbols in total? :: L

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Number of combinations

L

n

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• Letters, digits, and 10 symbols :: n = 72
• Easy to memorize :: L = 10
• Combinations: 3.74 x 10^18
• 2-core CPU @ 2.0 GHz: 2 days

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• Lowercase letters only :: n = 26
• Very long :: L = 50
• Combinations: 5.61 x 10^70
• 2-core CPU @ 2.0 GHz: 1.62 x 10^56 days

Size matters more

How to make
good password?

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Make it random

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Humans memorise stupid shit easily

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Make it unique

How do you memorise all those passwords?

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You don't

Meet LastPass

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A randomly generated password for each service

Memorise a single password to unlock them all

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Your life in two passwords:

• E-mail
• Password manager

Two-factor authentication

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1. Login with password
2. Prove you have a device with you

Encrypt anything

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