Category: Security

Computer Security

  • Steganography software Cipher Image hides text in pictures

    Steganography software Cipher Image hides text in pictures

    Cipher Image let’s you hide plain text inside photos, a process known as steganography, it can hide messages of up to 64Kb in size, quite a few pages of information, the text has to be typed into the program, Cipher Image can not hide attached files. The data is hidden by replacing image pixels that are similar to each other making it unnoticeable to the human eye, the messages are encrypted using 128-bit, there is no mention of the algorithm used for this, images can be saved in 7 different file formats (jpeg, Gif, Tiff, Paintbrush, Windows Bitmap and OS/2 Bitmap), the included password generator can produce a random pass, it is not configurable and I did not find it useful as it will be impossible to remember whichever pass it produces, there is the option of saving the password in a .txt file but I would not advise it if the data is important.

    Cipher Image steganography software
    Cipher Image steganography software

    You will get tooltips with instructions when you hoover your mouse over the buttons, make sure to read them as the interface is not very intuitive it is easy to get lost, I would classify this tool as an adequate steganography program for low security stuff, mainly because it is not open source, the developers are not well known and the password generator is quite lousy, my only concern was encryption about which there is little information other than to say it uses 128bit, but people really won’t be able to spot any hidden text and that is what steganography is about, ideal to deliver secret messages using your Flickr or Picasa account, if you haven’t got any security agency going after you this program will get the covert communications job done.

    Visit Cipher Image homepage

  • Advanced SSH and SFTP client Bitvise Tunnelier

    Advanced SSH and SFTP client Bitvise Tunnelier

    Bitvise Tunnelier is a highly configurable Windows SSH client supporting TCP/IP tunnelling, in between others, it can be used as alternative to PuTTY for port forwarding for anonymous Internet browsing hiding your computer IP and getting around filters, there is integrated support for HTTP and Socks proxies, auto-reconnect, graphical SFTP with passive and active mode, FTP to SFTP bridge, client to server/server to client port forwarding, enabling/disabling encryption algorithms for SSH sessions, and saving of profiles. Terminal emulation supports vt100, xterm and bvterm terminals, the most common protocols in SSH servers, there is colour support for xterm and bvterm, RSA/DSA public key authentication, scriptable with a command line remote execution client.

    Optionally you can use Tunnelier in command line mode, this is normally use by IT administrators, it comes with flexible command lines able to load profiles on launching, it can be run in portable mode preventing any Windows registry changes. A .paf (PortableApps) and U3 (proprietary format specially designed for flash drives with the U3 Launchpad) portable Tunnelier made by users is available, though not supported by Bitvise.

    Bitvise Tunnelier SSH client
    Bitvise Tunnelier SSH client

    The makers of this software also develop WinSSHD (a Windows SSH server), Bitvise Tunnelier comes with features to remotely control it, Tunnelier supports speeds of up to 5 MB/s when connected to a WinSSHD server. If you are wondering how you could use this software to browse the Internet or access your email through an encrypted tunnel, be aware you will need an SSH server for that, Tunnelier is the tool that will allow you to connect to the tunnel just like OpenVPN software is the tool to allow you to connect to a VPN server.

    To get access to a SSH server for port forwarding, set up your own at home on a Windows computer with something like MobaSSH (not very difficult), learn Unix command line (advanced) and get a VPS, or find an SSH tunnel provider. I have used KiTTY and PuTTY to create SSH tunnels for Internet browsing and they both worked fine, but for high configuration and a nice GUI (interface), Tunnelier can not be beaten.

    Note: Bitvise Tunnelier is free for personal use and limited use inside organizations.

    Visit Bitvise Tunnelier homepage

  • Check your Internet browser security with Qualys’s BrowserCheck

    Check your Internet browser security with Qualys’s BrowserCheck

    Qualys Browsercheck is an online test run by a vulnerability assessment company (Qualys) that scans your Internet browser version and outdated plugins after visiting their website. In order to perform a security analysis you will be asked to install a browser plugin available for IE, Firefox and Chrome, that will show complete information about installed applications, like path and associated files. If you do not wish to install Qualys plugin you can opt for a quick online scan with limited information running in your browser, this will only check for browser version, Flash, Shockwave and Java.

    The results are neatly presented with an easy to understand colour code, if something has been found to be outdated you will be given a link to the official site from where to download an updated patched version of the software. After the updates have been applied you should rescan your Internet browser again to make sure everything went smoothly.

    Qualys Browsercheck security test
    Qualys Browsercheck security test

    If you can not update one of the vulnerable plugins installed in your browser, it is possible to disable them going into browser settings. The vsecurity test (with the browser plugin) includes the most used applications, like Adobe Flash Player, Sun Java, Shockwave, Apple Quicktime, Real Player, Adobe Reader and Windows Media Player together with inherent OS software like security updates, firewall and antivirus. Qualys security check plugin only works when you visit their Browsercheck website, you can uninstall it once you are done with it.

    The vulnerability test is also available for mobile devices like Android, iPhone and iPad as well as little known browsers like K-Meleon, Sleipnir, MineField and Maxthon. A BrowserCheck business edition with a unique URL for company employees allows network administrators to view detailed user browser vulnerabilities in the network. Data collected by Qualys in these security test is anonymized and statistically released showing which are the most outdated plugins on the Internet, according to this data, Java appears to be the most likely application to be run outdated, hence exposed to hacking attacks.

    Visit Qualys BrowserCheck homepage

  • Secure Profile password protect Google Chrome profile

    Secure Profile password protect Google Chrome profile

    Secure Profile is a Google Chrome addon that allows you set up a password to protect your entire Goggle Chrome profile, this is much better than other Chrome privacy addons like Link Password, which only encrypts your bookmarks. After entering a password inside Secure Profile options, before anybody can use your browser they will have to enter the password too, this extension can be used to stop people from using your Internet browser. Different profiles can be set up, all of them with a different password.

    You could use one profile/personality to visit certain sites, like news, and switch to a different profile for sites like porn, the advantage would be that tracking cookies on that specific profile will be isolated from others.

    Google Chrome Secure Profile addon
    Google Chrome Secure Profile addon

    This addon also protects your browser in Incognito mode when Google Chrome runs in RAM. It could be of use when sharing a computer at home to make sure everyone has their own settings and cookies, this is an easy solution to stop a noisy person from looking at your browser settings and history.

    Visit Secure Profile Chrome addon homepage

  • How cryptographic hashing functions work

    How cryptographic hashing functions work

    A cryptographic hash function is a one-way computational mathematical operation (aka checksum or digest) that takes a stream of data and returns a fix sized bit string known as cryptographic hash value, this value is unique, any small modification to the file will change it, for example, modifying a single pixel on a photograph will not be noticeable by the human eye but a cryptographic hashing of the picture will return value differing from the original.

    Cryptographic hashing algorithms are widely used in computer forensics to guarantee that files have not been tampered with, it can be compared to a digital fingerprint, security related software and Linux distributions normally come with a hash value, the user is meant to use a special program to calculate a hash value resulting from file he has just downloaded and make sure that it coincides with the string listed by the developer, if it doesn’t it means that the file been changed by someone or accidental data corruption occurred during the download, when two files have the same cryptographic hash value it is guaranteed that they are identical.

    Hash function diagram
    Hash function diagram

    Hashing a file does not mean to encrypt it, cryptographic algorithms used for encryption are totally different from those used for hashing files, encryption software like Truecrypt, gives two algorithm choices, one for encrypting the data and another to hash the user keyfile or password. Another use of cryptographic hashes is password storage, encryption software does not store user passwords in plain text, it creates a cryptographic function of a password, when the user wants to decrypt the data the software performs that operation again, if the cryptographic hashes coincide it then decrypts everything.

    SSL certificates contain a cryptographic hash to show its uniqueness, certification authorities use a hash algorithm to generate a certificate signature. Hashing algorithms can also be used to compare text, if the values coincide it assures content integrity this guarantees the receiver that the message has not been tampered with, in addition it is impossible to recreate the original message out of a hash string.

    Note: Flaws have been found in the MD5 algorithm, The United States Computer Emergency Readiness Team (US-CERT) considers the MD5 algorithm broken and unsuitable for use, the MD5 hashing algorithm should not be used in SSL certificates and digital signatures. Most U.S. government applications require SHA-2 hash functions (SHA-224, SHA-256, SHA-384, SHA-512), SHA-2 has been designed by the National Security Agency (NSA) and stands for Secure Hashing Algorithm.

    Cryptographic hashes and law enforcement

    Law enforcement agencies and RIAA sponsored investigators use hashing algorithms to track down those sharing illegal files in P2P networks, in the case of law enforcement, when they seize child pornography images, they automatically hash photos and videos storing the hash strings on a database,these unique values are compared with the cryptohashes of other previously seized files to see if it matches any of them.

    There are USB thumbdrives that can be plugged into a computer to scan its hard disk in search of files whose unique hashing algorithm matches one of the child pornography files previously seized, in a matter of minutes and without visually looking at the content law enforcement personnel can detect this kind of material, the same automatic software helps law enforcement to classify these images, when a new image not in the hashing database is found the software marks it for manual inspection to assess it.

    Law enforcement also owns specialist software that analyses P2P networks attempting to match a cryptographic hash file to one of those in their database of banned child pornography images, with very little supervision it is possible to detect child pornography, once a file has been flagged it is brought to the attention of an officer to start the process of tracking down the IP and gathering further evidence, the only flaw this has is that if someone modifies one of those photos using a graphics editor giving it a little more/less brightness, then the cryptographic files will not coincide. Software like ssdeep attempts to plug that gap by using a technique known as fuzzy hashing, this method can match cryptographic hashes of very similar files, if someone changes a single bit on a file, it would still pick it up, extreme file changes would not, the same technique can be used to detect similar malware files.

    RIAA sponsored companies can use cryptographic files to track down people sharing copyrighted material on P2P networks too, during their evidence gathering they will include a file hash value, if the case ever goes to court, after seizing the user’s computer, that unique hash string compared with the files in the computer will be solid evidence of guilt. Computer forensics software like Encase can create a cryptographic function of a computer hard disk as proof that the data not been tampered with when that hard disk gets to court or defence attorney.

    P2P network diagram
    P2P network diagram

    In order to make it more difficult for intellectual rights owners to prosecute violators, a new peer to peer system using Distributed Hash Table (DHT) to defeat automatic tracking systems has been implemented in BitTorrent and eMule (changing default settings is needed), instead of names, DHT uses hashing algorithms to index files, it makes it harder for the user to find the files he wants but adds an extra layer of privacy to filesharing, although not enough to make it impossible to track the infringer, DHT does not hide an individual’s identity.

    List of free hash and checksum calculators

    To cryptographically hash a file you will need to obtain special software to do that, select the file you would like to hash, from a 1bit file up to a full hard disk, choose the algorithm of your choice and hash it, the same software can also allow you to verify that hashing algorithms coincide (aka integrity check). If you do not want to download software, websites like Hashemall allow you to compute hashes online.

    FeeBooti: This free cryptographic hash value generator can computer all the common hashing algorithms (CRC32, MD5, Whirlpool, RipeMD160, SHA512, etc), simple to use interface, file integrity checksum for files of unlimited sizes, simultaneous checksum calculation using different algorithms, it copies hash values to Windows clipboard and integrates into windows property pages.

    Multihasher: Portable hash value calculator supporting CRC32, MD5, SHA1,SHA256,SHA384 and SHA512. It can be used for hash file verification and upload files to VirusTotal querying its database to find out if the file is malware. Multihasher integrates with Windows Explorer context menu, supports Unicode characters, file drag and drop and much more.

    Free checksum tool MultiHasher
    Free checksum tool MultiHasher

    HashGenerator: Beginner friendly application that can be installed or used as portable, to generate a hash file you simply right click on it using the context menu options or use the drag and drop feature. It computes 14 different type of checksums and can export a list of hashes to an HTML or .txt file.

    MD5Deep: Command line open source hashing tool for Windows, it can be compiled for other systems like Linux and BSD, MD5Deep can compute MD5, SHA-1, SHA256, Tiger and Whirlpool message digests, it can process regular files or block devices, it can recursively dig through the directory structure. This tool is best avoided by beginners.

  • Encrypted data backup with Powerfolder

    Encrypted data backup with Powerfolder

    Powerfolder is a free program for Windows, Mac and Linux to securely share, sync and backup your computer files, locally or in the cloud, if you choose to backup your data online you will be offered a free account with 1GB of free space, this is not necessary as the program can be used to do offline backups, if you decide to use the cloud option all data transfers will be encrypted using SSL (transfer) and AES (storage), to open an online account only requires entering an email address, which does not need to be verified, and the password of your choice.

    Powerfolder interface is easy to use, skinnable and with lots of configuration options, the software can be used to synchronize data in between computers on a LAN (Local Area Network) with real time data sync status showed on the screen, you can choose what to backup with a simple tick on a checkbox next to each folder.

    PowerFolder encrypted data backup
    PowerFolder encrypted data backup

    To share files online you just need to go to the Folders tab and follow the wizard where you will be offered what files to share and where to send an invitation key, in order for someone to access your data they will need to enter that secret key first. PowerFolder cloud storage can be accessed through the iPhone or Android through a specially made mobile portal (m.powerfolder.com), browser file downloads are made using an encrypted SSL connection, you can view and play audio files online too. Powerfolder software scans local folders for changes and uploads/erases the data as necessary, bandwidth taken by PowerFolder can be limited, a proxy and specific ports chosen, the plugins tab lets you configure advanced settings, like adopting UDT connections instead of TCP, encryption security level and setting up a dynamic DNS.

    I would have preferred it if the help manual wasn’t only available online, and the free 1GB online space is not enough to hold all of my important data, I could not find any other flaw to this very fine secure data backup software.

    Visit Powerfolder homepage

  • Google Chrome Ghost Incognito extension for privacy mode

    Google Chrome Ghost Incognito extension for privacy mode

    Ghost Incognito is a Chrome browser extension to make sure that certain websites are only opened in Incognito mode, Incognito mode (aka private browsing) in Google Chrome is activated using the CTRL+Shift+N and it stops your Internet browser from locally storing information about the websites you visit, like cookies, cache or history, all of your activities run in RAM memory and once you close the browser everything is gone for good. Firefox, Internet Explorer and Opera all have a privacy browser mode.

    Ghost Incognito Google Chrome
    Ghost Incognito Google Chrome

    The main benefit of Ghost Incognito is that you can browse the Internet normally at work or school and have the browser configured to visit sites like Facebook only using privacy mode avoiding leaving any recoverable passwords, usernames and Internet history in a public computer. By default, all porn .xxx domain names will open using Incognito mode. When you type a URL that has been set up to run in private mode a new window automatically opens, but I noticed that the first typed URL triggering Incognito mode is remembered by the browser, this is a flaw that I hope the developers can fix in next releases, another possible problem is that the URLs you have added to Ghost Incognito extension configuration will be visible by anyone with access to your Internet browser, I can see this extension being useful for a portable Google Chrome browser but not much more.

    Visit Ghost Incognito Chrome addon