Comments
Safely Storing User Passwords: Hashing vs. Encrypting
Newest First  |  Oldest First  |  Threaded View
TejGandhi1986
50%
50%
TejGandhi1986,
User Rank: Apprentice
6/13/2014 | 9:01:50 PM
Preventing the password file from getting stolen
Thanks for the article,itis very informative and provide details on the foundations related to hashing and encryption.

Considering different chain of thoughts ,along with encryption and hashing that is used to secure passwords it is essential that the password file is well protected SAM file in windows and etc/shadow or etc/passwd file in Linux access must be restricted with multiple layers of defense to prevent it from getting stolen.

Thanks

Tej Gandhi

 
MichaelCoates
100%
0%
MichaelCoates,
User Rank: Author
6/12/2014 | 4:16:00 PM
Re: Good overview
Good question. The stolen database would indeed include the salts. However, exposure of random per-user salts does not undermine their purpose and security benefits.

There are two benefits to using per-user salts

1. When using per-user salts an attacker cannot simply review the stolen password hash databse for duplicate hashes (which would indicate the same original password for both accounts). The introduction of a per-user salt ensures that even the same password will result in unique hashes.

2. An attacker cannot download a rainbow table and use it against the password hashes. A rainbow table is a large database of precomputed hashes for a variety of common passwords (or even all possible passwords of certain character sets and lengths). Without per-user salts an attacker could do a simple lookup of the stolen hash within the rainbow table to determine the original password. The introduction of per-user salts means the rainbow table is useless.


Sure, an attacker could incorporate the salt into a brute force attack. But the purpose of a salt isn't to stop brute force. It's to accomplish the two items mentioned above (duplicate hashes and rainbow tables). As I mentioned in the article, the iterative hashing approach that exists in bcrypt/scrypt/PBKDF2 is the defense against brute force attacks on the password hash.

 

Hope that helps.

Michael

 
chiefwilson
50%
50%
chiefwilson,
User Rank: Apprentice
6/11/2014 | 9:57:04 PM
Re: Good overview
Michael,

Thank you for a well-written article. I agree that hashing passwords with added salt provides far greater security than simply encrypting passwords. My question is simple: If a malicious actor steals a database of password hashes, won't this database include the salts as well, thereby nullifying the purpose of the salt, which is to defend against brute force dictionary and rainbow table attacks?
Marilyn Cohodas
100%
0%
Marilyn Cohodas,
User Rank: Strategist
6/4/2014 | 2:51:46 PM
Re: Good overview
Thanks, Michael. One of the things I've been hearing about more and more is that personal information has become much more valuable a target for cybercrime than, for example credit cards. If that's the case, then your message about hashing versus encryption is one that InfoSec pros should definitely take to heart. 
MichaelCoates
100%
0%
MichaelCoates,
User Rank: Author
6/4/2014 | 1:02:50 PM
Re: Good overview
The largest misconception is that since encryption is good for protecting information in some situations it is therefore appropriate for all situations involving sensitive data. As discussed above, encryption is really the wrong choice for protecting passwords.

Second, that any hashing algorithm is sufficient for password hashing. Selecting a weak algorithm like md5 or failing to user per user salts places passwords at extreme risk if the hash file is stolen.

-Michael
Marilyn Cohodas
100%
0%
Marilyn Cohodas,
User Rank: Strategist
6/4/2014 | 12:34:09 PM
Good overview
Thanks for your detailed overview, Michael. You say that to propertly secure user invormation today, application developers must starts with "a proper understanding of fundamental security controls and the protection of user passwords using modern hashing algorithms." What do you think is the biggest misunderstanding of security that app developers have?


Register for Dark Reading Newsletters
White Papers
Cartoon
Current Issue
Flash Poll
10 Recommendations for Outsourcing Security
10 Recommendations for Outsourcing Security
Enterprises today have a wide range of third-party options to help improve their defenses, including MSSPs, auditing and penetration testing, and DDoS protection. But are there situations in which a service provider might actually increase risk?
Video
Slideshows
Twitter Feed
Dark Reading - Bug Report
Bug Report
Enterprise Vulnerabilities
From DHS/US-CERT's National Vulnerability Database
CVE-2015-5084
Published: 2015-08-02
The Siemens SIMATIC WinCC Sm@rtClient and Sm@rtClient Lite applications before 01.00.01.00 for Android do not properly store passwords, which allows physically approximate attackers to obtain sensitive information via unspecified vectors.

CVE-2015-5352
Published: 2015-08-02
The x11_open_helper function in channels.c in ssh in OpenSSH before 6.9, when ForwardX11Trusted mode is not used, lacks a check of the refusal deadline for X connections, which makes it easier for remote attackers to bypass intended access restrictions via a connection outside of the permitted time ...

CVE-2015-5537
Published: 2015-08-02
The SSL layer of the HTTPS service in Siemens RuggedCom ROS before 4.2.0 and ROX II does not properly implement CBC padding, which makes it easier for man-in-the-middle attackers to obtain cleartext data via a padding-oracle attack, a different vulnerability than CVE-2014-3566.

CVE-2015-5600
Published: 2015-08-02
The kbdint_next_device function in auth2-chall.c in sshd in OpenSSH through 6.9 does not properly restrict the processing of keyboard-interactive devices within a single connection, which makes it easier for remote attackers to conduct brute-force attacks or cause a denial of service (CPU consumptio...

CVE-2015-1009
Published: 2015-07-31
Schneider Electric InduSoft Web Studio before 7.1.3.5 Patch 5 and Wonderware InTouch Machine Edition through 7.1 SP3 Patch 4 use cleartext for project-window password storage, which allows local users to obtain sensitive information by reading a file.

Dark Reading Radio
Archived Dark Reading Radio
What’s the future of the venerable firewall? We’ve invited two security industry leaders to make their case: Join us and bring your questions and opinions!