New answers tagged

-2

Hei. You might try Easylock.. You can definitively use it for Dropbox.


4

As @techraf and @josef commented, all DDoS providers have the same challenges: To effectively identify DDoS traffic, a mitigation provider needs to be connected inside your encryption termination point, or at least be a Man In the Middle. Your concern regarding CloudFlare is the same concern you should have with them all. If you want DDoS mitigation, ...


1

ChaCha20 and Salsa20 are stream ciphers. Their purpose is to providie confidentiality as long as the key used to seed them remains secret. Poly1305 however is a Message Authentication Code (MAC), which is supposed to provide integrity and authenticity for the sent messages. In general, it should be possible to use them seperately as they do not seem to ...


0

A way you can tie user credentials to the key is by having one key for the encrypted file, and encrypting that key multiple times with key based on each user's credentials. You'll have a ton of small key files (one per user), and each user who has access can decrypt the key to use in order to decrypt the final file.


0

You can determine all supported ciphers as: $ openssl ciphers -v | grep Camellia DHE-RSA-CAMELLIA256-SHA SSLv3 Kx=DH Au=RSA Enc=Camellia(256) Mac=SHA1 DHE-DSS-CAMELLIA256-SHA SSLv3 Kx=DH Au=DSS Enc=Camellia(256) Mac=SHA1 DH-RSA-CAMELLIA256-SHA SSLv3 Kx=DH/RSA Au=DH Enc=Camellia(256) Mac=SHA1 DH-DSS-CAMELLIA256-SHA SSLv3 Kx=DH/DSS Au=DH ...


2

Currently, RSA is still recommended as a gold standard (strong, wide compatible) ed25519 is good (independent of NIST, but not compatible with all old clients). Server is usually providing more different host key types, so you are targeting for compatibility. The order of priority in the client config is from the stronger to more compatible ones. ...


3

The requirement is to protect the data appropriately. Pre-auth, you are unlikely to have the CVV on disk (it should just be in RAM) but if you do, then yes you should encrypt, and then delete afterwards, so your assumption that "the restriction on storing sensitive authentication data applies to post authentication/processing storage" is incorrect.


0

For me it would feel a little awkward to ask him for a "MasterKey". It does not if the core of the service is to ensure that only that person can access the data by first decoding them. The authentication via an third party is in that case is not useful, you will be better off handing it (correctly) yourself so that the users have only one authentication ...


1

I think you just need to use PGP/GPG encryption and encrypt the archive using your private key (under the hood PGP/GPG will do the same as you described: it will generate a random symmetric key, encrypt the body of the payload with it, then will encrypt the symmetric key with your private asymmetric key). This will give you a single encrypted file. All ...


1

If your main objective is to ensure integrity and authenticity, and not confidentiality, it sounds like what you want is not encryption, but message authentication (symmetric, like HMAC) or a digital signature (asymmetric, like RSA). Since you mention third parties, it's likely that signing with an asymmetric system should be used, since with a symmetric ...


0

Is is difficult to to implement either? No not really, as long as you use a vetted and verified implemented library. AES is much faster than RSA, but as you only sign a hash the amount of data operated on should not be much of a concern. RSA (is that is the assym. alogrithm you wish to use) is 2048 (see) and 256 for AES. With AES you would probably want to ...


0

Generally you shouldn't send private keys, but if you absolutely have to send a private key then encrypt it with the recipient's public key. Bear in mind that your recipient must be willing to take the risk that you could keep a copy of the private key.


0

No. Just no. You said: Sorry, I think it may not have been clear that the "hard drive" example was an example of the media degrading, not the message. IOW the hard drive was an "external factor" that you can easily overcome by copying the file. What I mean is that even if you copy the message, all the copies degrade at the same rate And this is ...


-4

Send the private key from an anonymous emailer service to a 48-hour throwaway email service address. You just need to publicly post your throwaway email address with the public-key in full sight of everyone and wait for your sender-partner to send you the PK within 48 hours. After 48 hours the throwaway evaporates. No one needs to trust anyone. The two ...


1

The PSK is not 'converted' to hexadecimal but if doing the calculation by hand it is often expressed that way to simplify the process. As the manpage indicates, wpa_passphrase pre-computes PSK entries for network configuration blocks of a wpa_supplicant.conf file. An ASCII passphrase and SSID are used to generate a 256-bit PSK This means, you ...


4

There's no question that this extra MD5 layer is better than just using the original password. The question is whether you'd be better off using a Password Manager which simply generates random passwords and stores them in encrypted form. I do see the elegance of your solution over a Password Manager. Since the final password is derived, not stored, then ...


2

There's a general principle that a hash function like MD5 cannot add entropy - which means that if this method was a tool, a piece of software that people attempting to discover the password became aware of, it would simply be another rule, another step in their attempts, and would only marginally slow them down. However, if this was a method that Bob ...


0

If you are asking whether UEFI compromises a PC physical access, or if it creates any kind of potentially dangerous logs requires further clarification. Every PC with Windows 8 or later uses UEFI as part of its licensing requirement. UEFI Secure Boot in Win10 validates programs before execution.If you have to dual boot Win10 and Linux then linux require a ...


1

The presence of some security controls does not make a system secure. Yes I think you have identified a valid problem but that organization could still truthfully say the confidential data was never sent in an unencrypted fashion. Unfortunately there are many vendors touting things as being secure because they either have some security controls or because ...


2

One of the biggest issues that you face is not the algorithms you choose, but how you implement using them. There are many good algorithms for various purposes, and virtually any of them, improperly applied, can result in a disastrously broken cryptosystem. This is one of the reasons people offer advice like "use libsodium" because libraries like ...


-1

plain dm-crypt does not use salt, wich means that if you cipher the same data with the same password you end up with the same result. That is a big weakness, specialy if the attacker knows you encrypted a file system, he can gess how your data look and try keys to see if it matches.


5

Many printers, especially those used in businesses, support IPP over HTTPS. If you have access to the printer's control panel, you can enable HTTPS and install a certificate that you trust. On your computer, set up a printer manually and specify https://printer-domain or printer-domain:443 as the printer's address, depending on what operating system you are ...


2

Most printers support IPP (Internet Printing Protocol). From the wiki: Unlike other printing protocols, IPP also supports access control, authentication, and encryption, making it a much more capable and secure printing mechanism than older ones.


2

Yes, but don't do it. If you are asking if it is possible to come up with a proprietary scheme for encrypting data that only your application "knows," the answer is yes, until someone figures out how to reverse-engineer it (which is usually easier than you realize). This sort of practice is known as security by obscurity and is highly discouraged. Instead,...


3

The two code snippets will very likely compile to the exact same bytecode, so no difference. Even if it wasn't the case, passwd contains only a reference to the string containing the password, no extra copy of the value is created.


1

Something like this was actually done in some versions of the RAR compression software (in the early days, not sure if it still is like this). An encrypted archive would be decrypted by any password entered, but a wrong password would result in gibberish output. It was done to prevent brute-forcing of passwords which at the time was feasable for ZIP archives ...


3

There are several ways to do this but basically you are describing something of a digital rights management problem. There are some open-source DRM programs like OpenIPMP which may help but there are probably other ways to solve your problem without using DRM. https://sourceforge.net/projects/openipmp/ You didn't provide a lot of information about your ...


0

Agree they are different, but some of the answers are more about typical implementations rather than basic differences. Seems to me encryption info (algorithm, key, etc) are attributes of data, clear data is just a special case. Access control takes care of who can do what to some data and to its attributes. It should make sense for access control to say "...


4

Sounds like you're talking about a form of "deniable encryption" or "plausible deniability" in the context of crypto; that is, an alternative secret that decrypts to plausible but non-authentic plaintex. See https://en.wikipedia.org/wiki/Deniable_encryption for details. But strictly speaking, if someone has the capability to bruteforce your ciphertext, they ...


6

The effect is tiny Let's suppose that your system transforms practical brute force from decrypting the first four bytes (realistically, the first much larger block, but whatever) to having to decrypt the full e.g. four gigabytes of encrypted data, making bruteforce attempts approximately billion times or 2^30 times slower. Now, that might seem a big ...


1

For remote access, as others have said, simple lockouts and delays can work. For passwords, what you have is a one-way hash. To validate the password, you re-hash it, and compare the two hashes. Having more than one simple password produce a valid match against a single hash is considered undesirable: it means the hash is weak, and has "collisions". So it'...


5

Most already has been said, I just want to offer another perspective. Imagine you would try to secure a house with this technique. You would let the intruder give access to a cellar room if he tries to open the door for some time. The question is, would you want an intruder even there? The intruder will most certainly realize that he didn't get what he ...


2

The problem with keys is they exist as data and not as running code. Even with the CA and Crichton example, what happens is an out of band procedure occurs that provides you with reasonable responses for each decryption try. Mathematically this is impossible on the level of a ciphertext and brute force attempts.


42

Fooling an attacker with false positives isn't a bad idea, and it's not new. The following may interest you. Cryptographic Camouflage CA technologies has patented a technology known as Cryptographic Camouflage. A sensitive point in public key cryptography is how to protect the private key. We outline a method of protecting private keys using ...


13

To give you a straight answer, yes, it is possible to reduce the effectiveness of brute-force attacks and it can be done the way you suggested, but shouldn't. You can get very similar results just by implementing timing delays between each failed attempt and the next guess. Also, (just for your knowledge) very sophisticated and similar technologies have ...


105

The answer always depends on your threat model. Security is always woven into a balance between security and usability. Your approach inconveniences the hackers trying to break into the account, but also inconveniences a user who merely mistypes their password. If the fake account is believable enough to fool an attacker, it may also be believable enough ...


0

I just wanted to append my thoughts to this since I've been recently going through the same thing. All my attempts of trying to get ECDHE with SunEC have been pretty unsuccessful, so I'd strongly recommend just using Bouncy Castle. You just add the provider jar to your JRE/JDK ext folders and modify your security providers in your java security file and ...


1

Why not send him by Email? I might be missing something here but I believe that if you have a strong enough password and 2 factor authentication then using any of the big email providers that use HTTPS (Gmail, Outlook, Yahoo, etc..) should be perfectly fine and secure. Either way it's not like someone can do much with your bank information. The following ...


1

Here are some general considerations regarding bigger architecture in case more servers could be used to reduce attack surface. In the above scenario, if the single server is compromised, it may reveal sensitive data over period of time when admin users are logging-in. There could be two web servers - one for clients and one for admins There could be ...


3

Passwords are concerned with system access. They are used to verify that you are who you say you are (example: logging into email), or at least that you are someone that is allowed to access the resource you are trying to access (example: a code to open a door). The important thing about passwords is that they are fed into a system, so extra measures like ...


0

Early forms of cryptography were based on secret encryption algorithms, but it soon became apparent that this was a terribly bad idea. If you suspect the algorithm is learned by the enemy then they can potentially decode everything and you have to throw it all away and start again. And algorithms are hard to think up. A better idea is to use a key. In a ...


1

I am not sure I can answer this question perfectly, but I'll try. First off, think of symmetric algorithms. One such algorithm is a method to encipher(encrypt) a message, and must be completed with a key, in order to tell the algorithm exactly how to encipher said message. The enciphered message is called cipher-text. The recipient of the cipher-text must ...


0

To my knowledge, a key is a password used to decrypt a message. The Key is built out of a Password Derivation function. The function (i.e. PBKDF2, or a repetetive SHA-256) is designed to take a notable amount of load. (i.e. 250ms) The derived Key is more difficult to guess than the original password (i.e. defend against a rented cluster trying to brute-...


2

There are commonly two methods of controlling drones. Radio receivers and data transceivers (traditionally telemetry links). This really varies by device, autopilot hardware, etc. Some even use WiFi for everything. Receivers typically are receive-only, and convert received signals into PPM or PWM signals to speed controllers, servos, etc. Transceivers ...


7

The full URL is protected by the end to end encryption of HTTPS, but the target IP and hostname (the full name of the host, i.e. FQDN, i.e. something like www.example.org) are not. Thus the router could get the name of the host you visit but not the full URL (i.e. not the path after the hostname): https://www.example.org/some/secret/page.html |-- ...


1

I actually tried this with my neighbor who is connected to same ISP. PPPoE required 3 things: Username Password MAC if Binding is enabled by your ISP I was able to get these things from my neighbor. I spoofed the MAC address, started PPPoE connection with his credentials. And BOOM I was able to use his IP. But before that the PPPoE session of my ...


1

The encryption key for full disk or partial disk encryption are stored in RAM while the OS is operational. How are the disk encryption keys protected when a laptop is locked? If the device is shut down, then RAM is cleared, thereby securing your keys. If RAM is really cold, it will last awhile longer, so one technique to extracting RAM is to freeze ...


5

Short answer is "data STILL readable but just behind a password". It is rare that anything in RAM is encrypted, simply because it would require some sort of a password to decrypt, and most passwords would reside in RAM anyhow. Going a bit further with this, the decryption password for the majority of disk-encryption programs would actually also (ironically)...


0

AFAIK there is no way around it. You have to boot into the old system, export the certificate with the corresponding private key and save it (I saved it as PFX). I then brought the file into another system (BTW a different laptop, thus different TPM) and logged in using the same username & pword as the previous machine. I was able to successfully import ...


0

When it comes to overwriting data, there's so much that the filesystem and hardware do for optimizations that cause issues. If it's a HDD, an overwrite of free-space will do it (if you've gotten rid of all caches, backups, etc, and deleted the unencrypted file). If it's a SSD/flash-drive, there is no sanitization procedure besides "Kinetic Sanitization" (i.e....



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