Every other week there seems to be a new dump of cracked passwords, hurting innocent and unbeknownst users. It seems as if keeping users passwords safe is a herculean task, even beyond the most resourceful organizations. However, it doesn't have to be. Password hashing is an important discipline in cryptography. Securing passwords has become so integral to our society that in 2013 a Password Hashing Competition was announced, for the academic community to band together and develop a common recommendation for future use. In this talk, I'll showcase how to handle passwords correctly and safely and clear out misinformation that still abounds in tutorials and blog posts. All with heaps of demos to motivate, make the material concrete and so everyone can follow along!

1. Title
Name and surmane of speaker
Company
Password Hashing
Emil Bay
CommodiTrader

2. !
Technical Founder, CommodiTrader
@emilbayes

4. Passwords

5. Proves your identity

6. ! " # $ % &

7. ☠

8. 1. No security holes
2. Unique passwords
3. Safer storage

9. 1. No security holes
2. Unique passwords
3. Safer storage

11. Johannes Bader, hacker_two, CC BY 2.0

12. Plaintext

14. Problems:
Plaintext!
Solution:
Obscure password

15. Hash
1. Deterministic
2. Pre-image resitant (one-way)
3. Second pre-image resitant (voluntary collisions)
4. Collision resistance (involuentary collisions)

16. {0,1}* ↦ {0,1}n

17. MD5
SHA-1
SHA-2 (SHA-256 & SHA-512)
Blake2
SHA-3 (Keccak)
bcrypt, scrypt
Argon2

18. var crypto = require('crypto')
var hash = crypto.createHash('md5')
.update(password)
.digest()

20. var words = //...
var rainbowTable = words.map(function (word) {
return crypto.createHash('md5')
.update(word)
.digest()
})
var idx = indexOf(hash, rainbowTable)
var plaintext = words[idx]

21. Problems:
Rainbow Tables
Solution:
Make identical passwords
unique hashes

22. Salted Hash
Makes precomputation impractical
aka Rainbow Tables

23. var crypto = require('crypto')
var salt = crypto.randomBytes(64)
var hash = crypto.createHash('md5')
.update(salt)
.update(':')
.update(password)
.digest()

25. Problems:
Still too efficient
Solution:
Expend more resources

26. Iterated Hash
NIST compliant

27. var crypto = require('crypto')
var salt = crypto.randomBytes(128)
var iter = 10000
var hashLen = 512
var algo = 'sha512'
crypto.pbkdf2(password, salt, iter, hashLen, algo, function (err, hash) {
// ...
})

29. Problems:
Very easy to parallelize
Solution:
Make even more expensive!

30. KDF
*Key Derivation Function
Purposefully slow
Uses lots of memory and computation

31. npm install secure-password

32. Argon2
Winner of PHC

33. Problems:
Blocks event loop
Solution:
Use async API

34. var pwd = require('secure-password')()
var userPassword = Buffer.from('my-password')
pwd.hash(userPassword, callback)

35. var sodium = require('sodium-native')

36. var sodium = require('sodium-universal')

37. var SecurePassword = require('secure-password')

38. var SecurePassword = require('secure-password')