CRYPTOGRAPHY WITH PHP
MARK NIEBERGALL
ZendCon 2017 Workshop
https://joind.in/talk/7b305

CRYPTOGRAPHY WITH PHP
ABOUT MARK NIEBERGALL
▸ PHP since 2005
▸ Masters degree in MIS
▸ Senior Software Engineer
▸ Drug screening project
▸ UPHPU President
▸ SSCP, CSSLP Certified and SME
▸ Drones, fishing, skiing, father, husband

CRYPTOGRAPHY WITH PHP
ABOUT MARK NIEBERGALL

CRYPTOGRAPHY WITH PHP
ABOUT MARK NIEBERGALL

CRYPTOGRAPHY WITH PHP
ABOUT MARK NIEBERGALL

CRYPTOGRAPHY WITH PHP
OBJECTIVES
▸ Time on the keyboard
▸ Learn about and use PHP cryptography and hashing
libraries
▸ Security considerations with implementation

CRYPTOGRAPHY WITH PHP
OBJECTIVES
▸ Coding time!
▸ Various modules
▸ Estimated time (5, 10, or 15 minutes)
▸ Cryptography games will apply what was covered

CRYPTOGRAPHY WITH PHP
SCHEDULE
▸ 9:00-9:30 Setup and covering slides that including terminology and
cryptography
▸ 9:30-9:50 PHP hash, password hashing
▸ 9:50-10:00 Break, lock picking
▸ 10:00-10:50 CSPRNG, OpenSSL
▸ 10:50-11:00 Break, more lock picking
▸ 11:00-11:15 libsodium
▸ 11:15-11:55 Cryptography Games
▸ 11:55-12:00 Regroup and conclusion

CRYPTOGRAPHY WITH PHP
OVERVIEW
▸ Environment Setup
▸ Why Cryptography
▸ Definitions
▸ Role of Cryptography
▸ Algorithms
▸ Encryption with PHP
▸ Considerations
▸ Cryptography Games

CRYPTOGRAPHY WITH PHP
ENVIRONMENT SETUP

CRYPTOGRAPHY WITH PHP
ENVIRONMENT SETUP
▸ PHP 5.5+, best is 7.0+
▸ Ideally have libsodium PECL extension (see https://
paragonie.com/book/pecl-libsodium/read/00-
intro.md#installing-libsodium) or 7.2 (RC)
▸ Once you are up and running, please help others
▸ Worse case, use https://3v4l.org/

CRYPTOGRAPHY WITH PHP
WHY CRYPTOGRAPHY

CRYPTOGRAPHY WITH PHP
WHY CRYPTOGRAPHY

CRYPTOGRAPHY WITH PHP
WHY CRYPTOGRAPHY

CRYPTOGRAPHY WITH PHP
WHY CRYPTOGRAPHY

CRYPTOGRAPHY WITH PHP
WHY CRYPTOGRAPHY
▸ Over 100,000 incidents in 2016 with 3,141 confirmed
breaches
▸ Attacks largely for financial gain
▸ Many going after sensitive data

CRYPTOGRAPHY WITH PHP
WHY CRYPTOGRAPHY
▸ Review Verizon 2017 Data Breach Investigations Report
▸ Yearly report
▸ Cybersecurity investigations report
▸ Pulls from many sources
▸ Lots of informative charts

CRYPTOGRAPHY WITH PHP
WHY CRYPTOGRAPHY

CRYPTOGRAPHY WITH PHP
WHY CRYPTOGRAPHY
Incidents by industry

CRYPTOGRAPHY WITH PHP
WHY CRYPTOGRAPHY

CRYPTOGRAPHY WITH PHP
WHY CRYPTOGRAPHY

CRYPTOGRAPHY WITH PHP
WHY CRYPTOGRAPHY

CRYPTOGRAPHY WITH PHP
WHY CRYPTOGRAPHY

CRYPTOGRAPHY WITH PHP
WHY CRYPTOGRAPHY

CRYPTOGRAPHY WITH PHP
WHY CRYPTOGRAPHY
▸ No organization is immune
▸ Cryptography significantly reduces breach cost
▸ Cryptography can prevent leak of actual sensitive data

CRYPTOGRAPHY WITH PHP
WHY CRYPTOGRAPHY
▸ Attack Countermeasures
▸ Good password policy
▸ Encrypt sensitive data
▸ Encrypt computer disks and devices
▸ Keep current with patches

CRYPTOGRAPHY WITH PHP
DEFINITIONS

CRYPTOGRAPHY WITH PHP
DEFINITIONS
▸ Cryptography
▸ The process of writing or reading secret messages or
codes
▸ Classical cryptography started thousands of years ago
▸ Advanced during wars of 20th century
▸ The science or study of secret communications

CRYPTOGRAPHY WITH PHP
DEFINITIONS
▸ Encryption
▸ To change information from one form to another
especially to hide its meaning
▸ En: to make
▸ Crypto: secret or hidden
▸ The actual changing of a communication

CRYPTOGRAPHY WITH PHP
DEFINITIONS
▸ Algorithm
▸ A set of steps that are followed in order to solve a
mathematical problem or to complete a computer
process

CRYPTOGRAPHY WITH PHP
DEFINITIONS
▸ Cipher
▸ A way of changing a message to keep it secret
▸ An algorithm used to encrypt or decrypt
▸ Classically included substitution and transposition
▸ A becomes 1
▸ A becomes Z
▸ Abc123 becomes 123Abc
▸ Backwards

CRYPTOGRAPHY WITH PHP
DEFINITIONS
▸ Hash
▸ To chop into small pieces
▸ Maps data to a string
▸ One-way hash functions
▸ Schneier “workhorses of modern cryptography”
▸ Input is the message, output is the digest

CRYPTOGRAPHY WITH PHP
ROLE OF CRYPTOGRAPHY

CRYPTOGRAPHY WITH PHP
ROLE OF CRYPTOGRAPHY
▸ World War II
▸ Enigma Machine used by Nazi Germany
▸ Code breaking by Allies, including Alan Turing

CRYPTOGRAPHY WITH PHP
ROLE OF CRYPTOGRAPHY
▸ Secure communications from third parties
▸ Confidentiality of communications

CRYPTOGRAPHY WITH PHP
ROLE OF CRYPTOGRAPHY
▸ Secure data at rest
▸ Secure data in transit

CRYPTOGRAPHY WITH PHP
ROLE OF CRYPTOGRAPHY
▸ First 2 A’s in the AAA Framework
▸ Authentication: credentials
▸ Authorization: encrypt and decrypt data
▸ Accounting

CRYPTOGRAPHY WITH PHP
ALGORITHMS

CRYPTOGRAPHY WITH PHP
ALGORITHMS
▸ One Way Hash

CRYPTOGRAPHY WITH PHP
ALGORITHMS
▸ One Way Hash
▸ Data is hashed
▸ Cannot go backwards
▸ Integrity checks
▸ Password checks
▸ Identifiers; ex: Git and Mercurial

CRYPTOGRAPHY WITH PHP
ALGORITHMS
▸ One Way Hash
▸ MD5
▸ SHA-1, SHA-2, SHA-3

CRYPTOGRAPHY WITH PHP
ALGORITHMS
▸ Symmetric-Key

CRYPTOGRAPHY WITH PHP
ALGORITHMS
▸ Symmetric-Key
▸ Same key to encrypt and decrypt
▸ Shared secret key
▸ Susceptible to plaintext attacks (known and chosen) and
cryptanalysis (differential and linear)

CRYPTOGRAPHY WITH PHP
ALGORITHMS
▸ Symmetric-Key
▸ DES
▸ Triple DES
▸ AES

CRYPTOGRAPHY WITH PHP
ALGORITHMS
▸ Symmetric-Key
▸ Blowfish
▸ Twofish
▸ Threefish

CRYPTOGRAPHY WITH PHP
ALGORITHMS
▸ Asymmetric-Key

CRYPTOGRAPHY WITH PHP
ALGORITHMS
▸ Asymmetric-Key
▸ Heavily used in cryptography
▸ Public and private keys
▸ Public key is publicly available
▸ Private key is kept secret

CRYPTOGRAPHY WITH PHP
ALGORITHMS
▸ Asymmetric-Key

CRYPTOGRAPHY WITH PHP
ALGORITHMS
▸ Asymmetric-Key
▸ Public key used to authenticate messages from owner of
the private key
▸ Public key used to encrypt message to send to owner of
the private key
▸ Private key used to decrypt inbound messages
▸ Private key used to encrypt outbound messages

CRYPTOGRAPHY WITH PHP
ALGORITHMS
▸ Asymmetric-Key (Public-Key)
▸ RSA
▸ DSA

CRYPTOGRAPHY WITH PHP
ALGORITHMS
▸ Broken
▸ DES
▸ MD2, MD4, MD5
▸ SHA-1
▸ GOST
▸ Panama
▸ RC4

CRYPTOGRAPHY WITH PHP
ENCRYPTION WITH PHP

CRYPTOGRAPHY WITH PHP
ENCRYPTION WITH PHP
▸ String functions just don’t cut it
▸ bin2hex
▸ strrev
▸ base64_encode
▸ dechex
▸ ord and chr (ASCII)
▸ str_replace

CRYPTOGRAPHY WITH PHP
ENCRYPTION WITH PHP
▸ Hash
▸ Password hashing
▸ mcrypt
▸ CSPRNG
▸ openssl
▸ libsodium
▸ StupidPass

CRYPTOGRAPHY WITH PHP
ENCRYPTION WITH PHP
▸ Hash
▸ hash_algos for array of options
▸ hash($algorithm, $message, $raw = false);
▸ hash_file for file contents hash
▸ hash_equals for comparing hashed values

CRYPTOGRAPHY WITH PHP
ENCRYPTION WITH PHP
▸ Hash - Coding time!
▸ 5 minutes
▸ hash_algos for array of algorithms
▸ Output available algorithms
<?php
print_r(hash_algos());
▸ See https://en.wikipedia.org/wiki/
Comparison_of_cryptographic_hash_functions

CRYPTOGRAPHY WITH PHP
ENCRYPTION WITH PHP
▸ Hash - Coding time!
▸ 10 minutes
▸ hash($algorithm, $message, $raw = false);
▸ foreach hash_algos generate hash
▸ Review output content, including characters, length
▸ Does different message or message length impact hash
length?

CRYPTOGRAPHY WITH PHP
ENCRYPTION WITH PHP
▸ Hash - Coding time!
▸ 5 minutes
▸ hash_file for file contents hash
▸ make a text file with some text in it
▸ compare with hash of plain text

CRYPTOGRAPHY WITH PHP
ENCRYPTION WITH PHP
▸ Hash
▸ == and === are not timing safe comparisons
▸ Nuances with PHP == returning true
var_dump(md5('240610708') == md5(‘QNKCDZO'));
var_dump(md5('aabg7XSs') == md5('aabC9RqS'));
var_dump(sha1('aaroZmOk') == sha1('aaK1STfY'));
var_dump(sha1('aaO8zKZF') == sha1('aa3OFF9m'));
var_dump('0010e2' == '1e3');
var_dump('0x1234Ab' == '1193131');
var_dump('0xABCdef' == ' 0xABCdef');

CRYPTOGRAPHY WITH PHP
ENCRYPTION WITH PHP
▸ Hash - Coding time!
▸ 15 minutes
▸ hash_equals as a timing safe hash comparison
▸ run thousands of iterations, look for patterns with averages
▸ $timeStart = microtime(true); … $timeEnd =
mircotime(true);
▸ array_multisort($timing, SORT_NUMERIC);

CRYPTOGRAPHY WITH PHP
ENCRYPTION WITH PHP

CRYPTOGRAPHY WITH PHP
ENCRYPTION WITH PHP

CRYPTOGRAPHY WITH PHP
ENCRYPTION WITH PHP

CRYPTOGRAPHY WITH PHP
ENCRYPTION WITH PHP
▸ 10 minute break
▸ Lock picking

CRYPTOGRAPHY WITH PHP
ENCRYPTION WITH PHP
▸ CSPRNG

CRYPTOGRAPHY WITH PHP
ENCRYPTION WITH PHP
▸ CSPRNG
▸ Cryptographically Secure Pseudo-Random Number
Generator (CSPRNG)
▸ Part of PHP 7 core
▸ For PHP < 7:
composer require paragonie/random_compat

CRYPTOGRAPHY WITH PHP
ENCRYPTION WITH PHP
▸ CSPRNG - Coding time!
▸ 10 minutes
▸ random_bytes($length)
▸ bin2hex($randomBytes) for human readable version
▸ random_int($min, $max)
▸ PHP_INT_MIN and PHP_INT_MAX

CRYPTOGRAPHY WITH PHP
ENCRYPTION WITH PHP

CRYPTOGRAPHY WITH PHP
ENCRYPTION WITH PHP

CRYPTOGRAPHY WITH PHP
ENCRYPTION WITH PHP

CRYPTOGRAPHY WITH PHP
ENCRYPTION WITH PHP

CRYPTOGRAPHY WITH PHP
ENCRYPTION WITH PHP
▸ Password hashing

CRYPTOGRAPHY WITH PHP
ENCRYPTION WITH PHP
▸ Password hashing
▸ $insecure = md5($password);
▸ Too fast
▸ Brute force
▸ 5f4dcc3b5aa765d61d8327deb882cf99

CRYPTOGRAPHY WITH PHP
ENCRYPTION WITH PHP
▸ Password hashing
▸ Anthony Ferrara RFC in 2012 to simplify password hashing
▸ Use password_hash and password_verfiy (PHP 5.5+)
▸ $current = password_hash($password,
PASSWORD_DEFAULT);
▸ PASSWORD_DEFAULT can change over time, currently is
blowfish, max password length of 72
▸ $isValid = password_verify($password, $current);

CRYPTOGRAPHY WITH PHP
ENCRYPTION WITH PHP
▸ Password hashing
▸ Salt generated automatically
▸ Deprecated as option in PHP 7
▸ Option ‘cost’, target time it takes
▸ password_hash($password, PASSWORD_DEFAULT,
[‘cost’ => 10]);

CRYPTOGRAPHY WITH PHP
ENCRYPTION WITH PHP
▸ Password hashing - Coding time!
▸ 10 minutes
▸ password_hash($password, PASSWORD_DEFAULT, [‘cost’ => 10]);
▸ notice output pattern, repeat for same password, try variations,
different costs
▸ $2y$10$i49TRWieyhYtQ6P.76R5aOwRisUIqnQJxS6tszUobVkGG8bP9/XsW
▸ $2y$ for algorithm
▸ 10 for cost
▸ 22 character salt, varies by algorithm
▸ Hash as the rest

CRYPTOGRAPHY WITH PHP
ENCRYPTION WITH PHP
▸ Password hashing - Coding time!
▸ 10 minutes
▸ password_verify($plaintext, $hash);
▸ password_needs_rehash($hash, PASSWORD_DEFAULT,
$options)
▸ Timing safe check

CRYPTOGRAPHY WITH PHP
ENCRYPTION WITH PHP

CRYPTOGRAPHY WITH PHP
ENCRYPTION WITH PHP

CRYPTOGRAPHY WITH PHP
ENCRYPTION WITH PHP

CRYPTOGRAPHY WITH PHP
ENCRYPTION WITH PHP
▸ mcrypt

CRYPTOGRAPHY WITH PHP
ENCRYPTION WITH PHP
▸ mcrypt
▸ Encrypt and decrypt
▸ Uses libmcrypt, which hasn’t been updated since 2007
▸ Bug fixes and patches
▸ Use libsodium or OpenSSL instead!

CRYPTOGRAPHY WITH PHP
ENCRYPTION WITH PHP
▸ openssl

CRYPTOGRAPHY WITH PHP
ENCRYPTION WITH PHP
▸ openssl
▸ Generate and verify signatures
▸ Certificate Signing Requests (CSR)
▸ Encrypt and decrypt data
▸ Actively supported

CRYPTOGRAPHY WITH PHP
ENCRYPTION WITH PHP
▸ openssl
▸ Private key generation
▸ openssl_pkey_new([$configs]);
▸ openssl_pkey_export_to_file($privateKey, $fileName);
▸ openssl_free_key($privateKey);

CRYPTOGRAPHY WITH PHP
ENCRYPTION WITH PHP
▸ openssl
▸ Configuration defaults to openssl.conf
▸ digest_alg: Digest method to use
▸ x509_extensions: Extensions to use for x509 cert
▸ req_extensions: Extensions to use for CSR
▸ private_key_bits: Bits for private key generation
▸ private_key_type: Type of key
▸ encrypt_key: Export key with passphrase
▸ encrypt_key_cipher: Cipher for key

CRYPTOGRAPHY WITH PHP
ENCRYPTION WITH PHP
▸ openssl - Coding time!
▸ 5 minutes
▸ Private key generation
▸ $config = [‘private_key_bits’ => 2048, 'private_key_type' =>
OPENSSL_KEYTYPE_RSA];
▸ openssl_pkey_new([$configs]);
▸ openssl_pkey_export_to_file($privateKey, $fileName);
▸ openssl_free_key($privateKey);

CRYPTOGRAPHY WITH PHP
ENCRYPTION WITH PHP

CRYPTOGRAPHY WITH PHP
ENCRYPTION WITH PHP

CRYPTOGRAPHY WITH PHP
ENCRYPTION WITH PHP
▸ openssl - Coding time!
▸ 5 minutes
▸ Public key generation
▸ Continue on from private key generation
▸ openssl_pkey_get_details($privateKey);
▸ file_put_contents(‘public.pem’, $details[‘key’]);
▸ Array with keys ‘bits’, ‘key’ (public key), ‘rsa’, ‘type’

CRYPTOGRAPHY WITH PHP
ENCRYPTION WITH PHP

CRYPTOGRAPHY WITH PHP
ENCRYPTION WITH PHP

CRYPTOGRAPHY WITH PHP
ENCRYPTION WITH PHP
▸ openssl - Coding time!
▸ 5 minutes
▸ Encrypting data with the public key, decrypt with private
▸ $isEncrypted = openssl_public_encrypt($message,
$encrypted, file_get_contents(‘public.pem’));
▸ $isDecrypted = openssl_private_decrypt($encrypted,
$decrypted, file_get_contents(‘private.pem’);

CRYPTOGRAPHY WITH PHP
ENCRYPTION WITH PHP
▸ openssl - Coding time!
▸ 5 minutes
▸ Encrypting data with the private key, decrypt with public
▸ $isEncrypted = openssl_private_encrypt($message,
$encrypted, file_get_contents(‘private.pem’));
▸ $isDecrypted = openssl_public_decrypt($encrypted,
$decrypted, file_get_contents(‘public.pem’);

CRYPTOGRAPHY WITH PHP
ENCRYPTION WITH PHP
▸ cracklib

CRYPTOGRAPHY WITH PHP
ENCRYPTION WITH PHP
▸ cracklib
▸ PECL extension, must be installed
▸ Checks complexity of passwords
▸ Still experimental

CRYPTOGRAPHY WITH PHP
ENCRYPTION WITH PHP
▸ cracklib
▸ crack_opendict(‘/path/to/dictionary’)
▸ crack_check($dictionary, $password)
▸ crack_getlastmessage()
▸ crack_closedict($dictionary)

CRYPTOGRAPHY WITH PHP
ENCRYPTION WITH PHP
▸ cracklib
▸ it's WAY too short
▸ it is too short
▸ it does not contain enough DIFFERENT characters
▸ it is all whitespace
▸ it is too simplistic/systematic
▸ it looks like a National Insurance number.
▸ it is based on a dictionary word
▸ it is based on a (reversed) dictionary word
▸ strong password

CRYPTOGRAPHY WITH PHP
ENCRYPTION WITH PHP
▸ 10 minute break
▸ Find group of up to 4 for games

CRYPTOGRAPHY WITH PHP
ENCRYPTION WITH PHP
▸ libsodium

CRYPTOGRAPHY WITH PHP
ENCRYPTION WITH PHP
▸ libsodium
▸ PECL extension
▸ PHP 7.2 core
▸ modern cryptography library
▸ namespaced as Sodiumfunction_name

CRYPTOGRAPHY WITH PHP
ENCRYPTION WITH PHP
▸ libsodium - Coding time!
▸ 10 minutes
▸ Cryptographically secure randomness
▸ Sodiumrandombytes_buf($numberBytes) with each byte being a
random value between 0 and 255 (bin2hex for readability)
▸ Sodiumrandombytes_random16() for random integer between 0
and 65535
▸ Sodiumrandombytes_uniform($maxPlusOne) for uniformly
distributed random integers between 0 and max

CRYPTOGRAPHY WITH PHP
ENCRYPTION WITH PHP
▸ libsodium - Coding time!
▸ 10 minutes
▸ Secret-key encryption and decryption
▸ $key =
Sodiumrandombytes_buf(SodiumCRYPTO_SECRETBOX_KEYBYTES);
▸ $nonce =
Sodiumrandombytes_buf(SodiumCRYPTO_SECRETBOX_NONCEBYTES);
▸ $ciphertext = Sodiumcrypto_secretbox('test', $nonce, $key);
▸ $plaintext = Sodiumcrypto_secretbox_open($ciphertext, $nonce, $key);

CRYPTOGRAPHY WITH PHP
ENCRYPTION WITH PHP
▸ libsodium
▸ Public-key encryption and decryption
▸ Sodiumcrypto_box_* functions

CRYPTOGRAPHY WITH PHP
ENCRYPTION WITH PHP
▸ libsodium
▸ Much more functionality
▸ Password hashing and checking
▸ Key signing
▸ Message Authentication Code (MAC)
▸ Hashing

CRYPTOGRAPHY WITH PHP
ENCRYPTION WITH PHP
▸ StupidPass

CRYPTOGRAPHY WITH PHP
ENCRYPTION WITH PHP
▸ StupidPass
▸ composer require northox/stupid-password
▸ $stupidPass = new StupidPass;
▸ $isValid = $stupidPass->validate($password);
▸ $stupidPass->getErrors();
▸ new StupidPass($maxLength, $environmental,
$pathToDictionary, $errorText, $options);

CRYPTOGRAPHY WITH PHP
ENCRYPTION WITH PHP
▸ StupidPass - Coding time!
▸ 10 minutes
▸ install composer, StupidPass
▸ Try out common passwords, custom dictionary, see the errors
▸ composer require northox/stupid-password
▸ $stupidPass = new StupidPass;
▸ $isValid = $stupidPass->validate($password);
▸ $stupidPass->getErrors();
▸ new StupidPass($maxLength, $environmental, $pathToDictionary, $errorText, $options);

CRYPTOGRAPHY WITH PHP
CONSIDERATIONS

CRYPTOGRAPHY WITH PHP
CONSIDERATIONS
▸ Salts
▸ Algorithm costs
▸ Timing attacks
▸ Brute force attacks
▸ Rainbow tables
▸ Max message length

CRYPTOGRAPHY WITH PHP
CONSIDERATIONS
▸ Salts
▸ Increased security for digest if done correctly
▸ Ex: $salt . $password
▸ Pepper debate
▸ Let password_hash generate the salt for you
▸ Different salt per password or message

CRYPTOGRAPHY WITH PHP
CONSIDERATIONS
▸ Algorithm Costs
▸ Default cost for password_hash is 10
▸ Higher cost leads to more processing time
▸ 8-12 is generally a good baseline
▸ Might change depending on hardware available

CRYPTOGRAPHY WITH PHP
CONSIDERATIONS
▸ Timing Attacks
▸ Analyzing timing for algorithms
▸ Time variation for hashing, encrypting, decrypting
▸ Ex: Username not found, no password check attempted
▸ Ex: String comparisons stop after first mismatch
▸ Timing safety built into functions, take same time for
positive or negative match

CRYPTOGRAPHY WITH PHP
CONSIDERATIONS
▸ Brute Force Attacks
▸ Timing attack used to brute force list of usernames
▸ Dictionary attack using dictionary and common
passwords
▸ Take time
▸ Advanced Persistent Threat (APT)

CRYPTOGRAPHY WITH PHP
CONSIDERATIONS
▸ Brute Force Attacks
▸ Countermeasures
▸ Lock accounts, but causes Denial of Service
▸ Add time to each login
▸ Lock by IP address
▸ Vary failed login attempt behavior (Ex: HTTP status,
redirect)

CRYPTOGRAPHY WITH PHP
CONSIDERATIONS
▸ Brute Force Attacks
▸ Countermeasures
▸ Key words in HTML comments (invalid login, bad
username or password)
▸ Security questions
▸ CAPTCHA
▸ Add another factor (multi-factor authentication)

CRYPTOGRAPHY WITH PHP
CONSIDERATIONS
▸ Rainbow Tables
▸ Table with hashes already figured out
▸ Used for hashing that always generates same hash for
an input
▸ Counter with modern algorithms, salts
▸ Common for MD5, SHA1, and other older algorithms

CRYPTOGRAPHY WITH PHP
CONSIDERATIONS
▸ Rainbow Tables
▸ Internet search for the hash
▸ Online hash cracking sites

CRYPTOGRAPHY WITH PHP
CONSIDERATIONS
▸ Max Message Length
▸ Only X characters considered when generating hash
▸ Ex: MD5 max is 128 characters in, 32 hex out
▸ Ex: password_hash max is 72 characters

CRYPTOGRAPHY WITH PHP
CONSIDERATIONS
▸ Identify sensitive data
▸ Determine appropriate encryption
▸ Use cryptography to keep data safe

CRYPTOGRAPHY WITH PHP
CONSIDERATIONS
▸ Cryptography can help minimize damage
▸ Electronic data breaches
▸ Stolen electronic devices
▸ Data transmission

CRYPTOGRAPHY WITH PHP
CONSIDERATIONS
▸ Cryptography cannot help minimize damage
▸ Phishing attacks
▸ Credential theft
▸ Escalation of privileges
▸ DoS/DDoS
▸ Social engineering

CRYPTOGRAPHY WITH PHP
CONSIDERATIONS
▸ Security education
▸ Verizon Data Breach Investigation Report
▸ SANS Institution, email digest
▸ Krebs on Security blog
▸ OWASP
▸ BrightTALK

CRYPTOGRAPHY WITH PHP
CRYPTOGRAPHY GAMES

CRYPTOGRAPHY WITH PHP
CRYPTOGRAPHY GAMES
▸ Groups of up to 4
▸ 11:15-11:20 Instructions and rules, get in groups
▸ 11:20-11:45 Coding time!
▸ 11:45-11:55 Review answers
▸ 11:55-12:00 Closing

CRYPTOGRAPHY WITH PHP
CRYPTOGRAPHY GAMES
▸ Get into your groups of up to 4

CRYPTOGRAPHY WITH PHP
CRYPTOGRAPHY GAMES
▸ Instructions and rules
▸ Use PHP
▸ Decrypt the data
▸ Record how you decrypted the message
▸ Record plain text answer
▸ Winning team is team with most correct answers

CRYPTOGRAPHY WITH PHP
CRYPTOGRAPHY GAMES
▸ Time is up!

CRYPTOGRAPHY WITH PHP
CRYPTOGRAPHY GAMES
▸ Answers

CRYPTOGRAPHY WITH PHP
CRYPTOGRAPHY GAMES
▸ Conclusion
▸ Leverage PHP cryptography and hashing features
▸ Use modern libraries
▸ Encrypt sensitive information
▸ Hash passwords correctly

CRYPTOGRAPHY WITH PHP
QUESTIONS?
▸ Rate on joind.in
▸ https://joind.in/talk/7b305

CRYPTOGRAPHY WITH PHP
SOURCES
▸ Merriam-Webster Dictionary online
▸ PHP.net documentation
▸ Virendra Chandak https://www.virendrachandak.com
▸ OWASP
▸ Verizon 2017 Data Breach Investigations Report
▸ https://paragonie.com/book/pecl-libsodium/read/00-intro.md
▸ https://www.cryptologie.net/article/268/how-to-compare-password-hashes-
in-php/
▸ http://blog.ircmaxell.com/2014/11/its-all-about-time.html