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How to Secure My Files
2020-08-05
Brice
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Network
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Network Security
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Network Security
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Network Security
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Network Security
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Network Security
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Network Security
How to Secure My Files
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The States of Digital Data
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The States of Digital Data
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How to Secure Your Secret
2019.05.08
Brice Bang
Buzzvil
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Security Chain
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How to save password securely
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The Updated Version of This Naver Blog
https://d2.naver.com/helloworld/318732
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Save as Plain Text
I don’t know
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Save as Plain Text
The hacker uploaded the database dump on PasteBin
Winwinsoft denied our proposal to negotiate with us.
But, we are generous and our window to negotiations
is still open.
We will disclose every information we have in a few
days if the negotiation is denied.
Until then, stay tuned :)
P.S. Here are some informations that we have.
It is dangerous because people generally use the same password on multiple services
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Key Derivation Function (KDF)
• It derives one or more secret keys from a secret value using pseudorandom function
• Has the characteristics for a password hash function
• DK = KDF(key, salt, iterations)
• ex)
• PBKDF2: NIST standard, government-friendly
• bcrypt
• scrypt
• argon2: Password Hashing Competition Winner
Master Key
KDF
Secret Key
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How About Buzzvil
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How About Buzzvil
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How to save password securely
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How to save password securely
A. Use argon2 or PBKDF2
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Our Solutions
1. How to create password securely
• Password generator
2. How to manage password securely
• Password manager
3. How to transfer password securely
• TLS 1.2+
4. How to save password securely
• argon2, PBKDF2
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Public PC on 3rd floor
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Please delete the accredited certificate after using the public PC
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Remaining Accredited Certificates in the Public PC on 4, Oct. 2020
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Cons of One-Way Hash Function – Speed
Original password can be found on average of
• 9.2 hours on a single core
• 1.15 hours on a 8 cores
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Hack the Accredited Certificates by Brute-force Attack
공인인증서 크래킹 - Inc0gnito
2015
6800 passwords per second in
Intel Core i7-4770
Millions per second are also
possible.
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The Safest Way, Degaussing or Destruct
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Prison: Welcome :)
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Deleted Files Can Be Recovered
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How the ‘Delete’ Function Works
Just marked. The building has not been destroyed, so it can be recovered.
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Overwrite
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Download Big File
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Zero-fill (Quick Format / Low Level Format)
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We’re Living in the Analog World
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In the analog world
Real value 11 -11 9 -9
Threshold 10 -10 10 -10
Read 1 0 1 1
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In the analog world
Real value 11 -11 9 -9
Ideal value 10 -10 10 -10
Read 1 0 1 1
Difference 1 -1 -1 1
Amplifier (x10) 10 -10 -10 10
Restored 1 0 0 1
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Increase the number of times the data is overwritten
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Software-based Overwriting Algorithms for Secure Erasing
● DoD 5220.22-M
● Gutmann method
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Software-based Overwriting Algorithms for Secure Erasing
● DoD 5220.22-M
• The standard of US
• Data is overwritten in order (example: ECE of BCWipe):
■ 0xD3 → 0x2C → random → a character → 0x95 → 0x6A → random
● Gutmann method
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Software-based Overwriting Algorithms for Secure Erasing
● DoD 5220.22-M
• The standard of US
• Data is overwritten in order (example: ECE of BCWipe):
■ 0xD3 → 0x2C → random → a character → 0x95 → 0x6A → random
● Gutmann method
• Designed by Peter Gutmann
• Write a series of 35 patterns
■ random 4 times -> 0x55 → 0xAA → 0x924924 → 0x492492 → 0x249249 →
0x00 → … → 0xFF →0x924924 → 0x492492 → 0x249249 → 0x6DB6DB →
0xB6DB6D → 0xDB6DB6 → random 4 times
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The Drawbacks of Erasing Algorithms
● Takes long time
● Reduces the lifetime of data storage
● Increases power consumption
● Post-treatment is easy to forget
● There are some cases we can’t do
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My Laptop was Stolen
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Erase or destroy my disk when I die
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Crypto-Shredding
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Crypto-Shredding
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Crypto-Shredding
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Crypto-Shredding
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How to Secure Your Secret
2019.05.08
Brice Bang
Buzzvil
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Trusted Platform Module (TPM)
● A key store for hardware authentication
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Secure Enclave
●
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Crypto-Shredding
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Disk Encryption
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Disk Encryption
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Requirement of Cipher for Disk Encryption
● Length-preserving
● AES-XTS
● AES-CBC-ESSIV
Disk OS
Encryption
Middleware
Write 4096 bytes
Write 4096 bytes
Read 4096 bytes
Read 4096 bytes
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Mac - FileVault
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Mac - FileVault - Performance
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Mac - FileVault - Performance
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Apple T2 Chip
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Mac - SSD is Encrypted by Default
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Windows Bitlocker Performance
HDD SSD
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Intel AES-NI Performance
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AES Performance using TrueCrypt
The max read speed of Samsung 980 PRO M.2 NVMe (1TB): 6,500MB/s
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Android
● How to support lots of devices which do not have hardware support for
AES?
○ For TLS, ChaCha20-Poly1305 was the choice of Google
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Adiantum: The ChaCha Stream Cipher in a Length-Preserving Mode
●
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iPhone
● On devices running iOS 4–iOS 7
○ Open the General settings and choose Passcode (or iTouch & Passcode).
○ Follow the prompts to create a passcode.
● On device running iOS 8 ~
○ Open the Settings app
○ Tap Touch ID & Passcode
○ Follow the prompts to create a passcode.
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Crypto-Shredding
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The Drawbacks of Erasing Algorithms
● Takes long time
● Reduces the lifetime of data storage
● Increases power consumption
● Post-treatment is easy to forget
● There are some cases we can’t do
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The Drawbacks of Disk Encryption
● Takes some time
● Increases power consumption
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References
● Data erasure
● Gutmann method
● Crypto-shredding
● 파일의 완전 삭제란 - 제로필과 DoD 5220.22-M 와이핑 (Chrome shows warning now)
● Caught On Camera: Berkeley Laptop Theft
● Block cipher mode of operation
● Ciphertext stealing
● Trusted Platform Module
● Secure Enclave overview
● 하드 드라이브 암호화 문제 해결
● Use FileVault to encrypt the startup disk on your Mac
● Do I Really Need FileVault? – MacMyths
● About the Apple T2 Security Chip
● About encrypted storage on your new Mac
● Does the BitLocker Encryption Impact Your Disk Performance?
● A Look at the Performance Impact of Hardware-Accelerated AES
● Introducing Adiantum: Encryption for the Next Billion Users
● 삼성전자, CES서 PCIe 4.0 M.2 SSD 980 Pro 시리즈 공개 : 기사 - 아이폰, 갤럭시S, 안드로이드 스마트폰을 위한
보드나라 모바일
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For the next...
● WPA Enterprise
● VPN
● DNS
● My Smart Home
● ...