IT Security Stack Exchange
IT Security Stack Exchange

Questions tagged [ciphers]

In cryptography, a cipher (or cypher) is an algorithm for performing encryption or decryption—a series of well-defined steps that can be followed as a procedure. An alternative, less common term is encipherment. To encipher or encode is to convert information into cipher or code.

141 questions
6
votes
1 answer

Disable RC4 ciphers best practice

To be compliant with security best practices, we have a requirement to disable RC4 ciphers. I have investigated a way to achieve this and, found that I can disable it by editing the registry…
kimo pryvt
  • 469
  • 4
  • 6
  • 12
6
votes
2 answers

SSL: Android may not verify hostname, defining cipher suites

I'm developing an Android App which sends some HTTPS requests to our own Webserver (Linux, Nginx, SSL zertificate from "Let's Encrypt"). The requests worked fine on my test devices (Android 4.2.2 & Android 6.0.1), but on another device (5.1.1) the…
Florian Mötz
  • 61
  • 4
5
votes
1 answer

Do ciphers and encoding schemes make passwords more secure?

I recently came across a tech professional advising a user to take some plaintext of their choice, run it through one of these ciphers, convert it to Base64, and then use the result as their master password on LastPass. However, the simple nature of…
Hashim Aziz
  • 969
  • 8
  • 21
5
votes
1 answer

Apache naming for TLS_RSA_WITH_3DES_EDE_CBC_SHA

According to NIST and HIPAA guidance, I miss one cipher on a new web server: TLS_RSA_WITH_3DES_EDE_CBC_SHA Despite I read this one is discouraged, I am curious as to how do I add it? I am on Linux Debian 9 with Apache. Currently I have set up…
LinuxSecurityFreak
  • 1,562
  • 2
  • 18
  • 32
5
votes
3 answers

Link between Cipher suites and certificate key

I'm trying to understand the SSL/TLS protocol and I'm lost on a specific point. What is the link between the public server key (eg. : "EC 256 bits" or " RSA 2048 bits") and the cipher suites ? This post give an answer : SSL certificates and…
Secu Noob
  • 53
  • 1
  • 4
5
votes
2 answers

TLS Version specific cipher suites

I have come across that GCM, CCM, SHA-256 and SHA-384 Cipher suites are TLS 1.2 only. So TLS handshake can not be performed with lower TLS version using these suites. I am trying to figure out supported cipher suites per protocol version (SSL v3,…
bhushan5640
  • 381
  • 3
  • 12
4
votes
2 answers

Apache TLS with only ECDHE-RSA-AES128-GCM-SHA256 enabled

Is there anything against this TLS-configuration in Apache: SSLProtocol TLSv1.2 SSLCipherSuite ECDHE-RSA-AES128-GCM-SHA256 There are lots of examples that use a more complicated setup, but I believe this configuration is both secure and easy to…
Gert-Jan
  • 145
  • 5
4
votes
2 answers

How are ciphers related to cryptographic algorithms like DES or AES?

It looks like I am having a terminology issue here. In cryptography, we have stream ciphers and block ciphers. I understand their difference. We also have cryptographic algorithms like AES (Rijndael). My confusion point is how do cryptographic…
py_script
  • 781
  • 2
  • 7
  • 10
4
votes
0 answers

HTTPS Cipher selection considerations

I went through various online docs, e.g. SSL and TLS Deployment Best Practices, regarding the "right" selection of cipher suites for a website. The attached picture shows my selection of cipher suites with lower priority from top to bottom, e.g.…
duxsco
  • 149
  • 2
4
votes
1 answer

Firefox & Chrome Strong Ciphers

Of the following ciphers for RSA authentication, Firefox and Chrome do not use stronger than ECDHE-RSA-AES128-SHA256. ECDHE-RSA-AES256-GCM-SHA384 TLSv1.2 Kx=ECDH Au=RSA Enc=AESGCM(256) Mac=AEAD ECDHE-RSA-AES128-GCM-SHA256 TLSv1.2 Kx=ECDH …
Geremia
  • 1,636
  • 3
  • 19
  • 33
4
votes
3 answers

Can browsers connect HTTPS w/ the NONE cipher?

I came across a mention of the NONE cipher being possible/available for HTTPS. Is it supported by any browsers for accessing any web-sites over the https:// address scheme? (What would be a snippet to create a test/one-time https server with the…
cnst
  • 1,884
  • 2
  • 19
  • 30
3
votes
1 answer

Can we add TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 on windows server 2012 using gpedit although not supported by windows OS by default?

We are using IIS on Windows 2012-R2 server to host dotnet apps. From the app, when we try connecting to an external 3rd party api we see TLS handshake failure. On running ssllabs test on that api, I see that they support only below suites. . On…
dhanush shetty
  • 33
  • 4
3
votes
1 answer

How to filter ciphers based on ssl certificate?

I have many ssl certificates. On one of the certificates I run the command openssl x509 -in cert.pem -text -noout it shows: Signature Algorithm: ecdsa-with-SHA256 Public Key Algorithm: id-ecPublicKey Based on the info from the certicate , how can I…
harsh3547
  • 33
  • 4
3
votes
2 answers

Cipher Suite TLS 1.2 - Weak in OHS

I am trying to correct weak encryption in TLS, by doing a test in SSL Labs, it throws weak encryption in the following chpher suite: Current Configuration: SSLCipherSuite HIGH:!MEDIUM:!LOW:!aNULL:!eNULL:!AES128:!SHA1 Cipher Suite TLS 1.2 - Weak:…
Ventur
  • 165
  • 1
  • 2
  • 6
3
votes
1 answer

Clarifications regarding ciphers and Nmap scan

I'm running the below Nmap command to test the strength of the cipher suites I have used in my host nmap -sV --script ssl-enum-ciphers -p 443 The Nmap doc says that Each ciphersuite is shown with a letter grade (A through F) indicating the…
Prakhash
  • 193
  • 2
  • 8
1
2
3
…
9 10