For questions about the step of the SSL/TLS handshake where the cipher is negotiated between the client and the server. This tag could also be used for questions about which ciphers to support in your application / configuration.

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17 views

IDEA and DES cipher suites support in TLS 1.2?

As per the following RFC IDEA and DES suites are removed from TLS 1.2 https://tools.ietf.org/html/rfc5469#section-1 https://tools.ietf.org/html/rfc5246#section-2 Still I have seen couple of servers ...
0
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1answer
14 views

Mode of operation are availables with Camellia

What cipher mode of operation are available using Camellia in a SSL certificate context ? I'm mostly interested if XEX (Xor-Encrypt-Xor) or related mode (LRW, XTS...) can be used because they seem ...
0
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1answer
42 views

Using ChaCha20 without Poly1305

Doing some lecture to choose a good configuration for my SSL certificate for my website (using a regular LAMP configuration), I'm wondering what are the possibles and secure alternative to poly1305 ...
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2answers
82 views

TLS version of cipher suite TLS_DHE_RSA_WITH_AES_256_CBC_SHA

I have a question related to the cipher suite TLS_DHE_RSA_WITH_AES_256_CBC_SHA (0x0039). It is first mentioned in RFC3268 in 2002. The highest available TLS version in 2002 was TLS 1.0 (RFC 2246). ...
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2answers
32 views

What parameters do I give cryptsetup?

I want to have an encrypted partition on my SSD. Benchmarks (a 100 samples of 100MiB each): Average read speeds: 418 MB/s Average write speeds: 386 MB/s # Tests are approximate using memory only (no ...
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1answer
59 views

Do current eCommerce systems provide sufficient security? [closed]

eCommerce systems are increasingly gaining importance in modern digital markets. Since most electronic transactions occur on a range of platforms, securing e-commerce transactions using Mobile Agents ...
2
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2answers
100 views

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 ...
4
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0answers
143 views

HTTPS Cipher selection considerations [closed]

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 ...
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0answers
37 views

ISO 9564 Approved Encryption Algorithms for PIN, why symmetric block ciphers?

I am currently researching best practices in designing a potential PIN management solution for a financial services application and began looking into ISO 9564 as a source of requirements. One of the ...
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2answers
30 views

logging available client side cipher suites from Apache tomcat?

When planning to remove a cipher suite, is there a way to log what cipher suites are available to the clients that talk to my web server? The idea is to know in advance that before some cipher is ...
0
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2answers
71 views

TLS_RSA_WITH_AES_128_CBC_SHA on Windows XP

Let me first say, I know XP is bad and dead. That said, I was wandering if a software written using .NET could make TLS 1.0 connections that use the TLS_RSA_WITH_AES_128_CBC_SHA when running on ...
3
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2answers
54 views

When moving beyond SSL3 is not possible, what cipher suites are immune to POODLE?

I understand that anything not using CBC will work, but are there any such modes? I'd also like to avoid weak stuff like RC4/5 and MD5 so preferrably ciphers that use sensible functions. On a SSL 3.0 ...
7
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1answer
138 views

Is the order of cipher suites related to the client's preferences ?

I am wondering if the order in which the cipher suites appear (from top to bottom) in the ClientHello message, and the client preference are relevant. So for example in the picture I have attached, is ...
1
vote
1answer
368 views

How to disable weak cipher suits in java application server for ssl

I have a custom Java application server running. I am seeing that there are some weak cipher suites supported by the server, for example some 112-bit ciphers. I want to disable those. Where can I do ...
2
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0answers
61 views

Openssl ciphers list sorting and removing

I was playing with a ciphers app to create example list of suites. Looking at the website (https://openssl.org/docs/manmaster/apps/ciphers.html) if I run one of the examples there: openssl ciphers -v ...
0
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2answers
268 views

Cipher suite selection for compatibility with http/2, and TLS 1.0-1.2

I have been attempting to configure my site to have http/2 support, but I kept having to remove cipher suites because of the blacklist. Eventually, I got the list whittled down sufficiently. The ...
9
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2answers
330 views

Why does Google prefer ECDHE-RSA-AES128-GCM-SHA256?

I want to configure my new mail server secure as possible and wondering about the used cipher while connecting to Googles SMTP server. I'm curious why they prefer the cipher ECDHE-RSA-AES128-GCM-...
3
votes
1answer
175 views

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 ...
5
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2answers
141 views

What are the use cases for anonymous SSL cipher suites?

SSL supports several anonymous cipher suites such as TLS_DH_anon_WITH_AES_256_GCM_SHA384. When these are used, no authentication is performed and no certificates are exchanged. This means that if they ...
4
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3answers
143 views

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 ...
0
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2answers
407 views

Bitwise cipher Cryptography

I'm doing an online cryptography course. There is a question in which it is given that the encrypted text for; OwBPAAQXAE9UC0FVBQxODgZSCUUMAQwCCApYRBJZBR0LDhoAGApPHQAUAQNZRAJPGwQbDQBDDREKQA== Is ...
0
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0answers
59 views

stream cipher & e-banking

As I read on internet, I ran into these two question. Yet, I thought about it but still don’t know how to tackle it. May I have your help? (a) During an e-banking transfer the bank uses a stream ...
20
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1answer
2k views

TLS Bicycle Attack - What cipher is free from flaws to use?

Recently a novel attack on TLS stream ciphers was developed by Guido Vranken, dubbed Bicycle and referenced in this Websense's blog post. It was based on a characteristic of stream ciphers that says ...
1
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1answer
122 views

How to change the default/preferred SSL cipher in Linux?

Is there any way I could change the default/preferred cipher for SSL, so that any application/process in Linux which uses SSL would have to use that specific cipher (RC4-SHA for example) for it's ...
6
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1answer
475 views

SSH ciphers, MAC and key-exchange (and pen-tests thereof)

At work we've been trying to move our external-facing services away from a policy of inclusivity (where we tried to accept as many people as possible) to a more security-focused setup. The first step ...
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3answers
307 views

SSL certificates using modern cipher suite vs obsolete cipher suite

I am shopping around for a SSL certificate and I took this screenshots from Chrome and Is the second site certificate showing errors less secure than the other not showing errors?
2
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1answer
228 views

What ciphersuites does Java 6 support out of the box that are not broken?

I have a legacy application which sits on Java 6(!), and talks to Apache 2.2.15 on RHEL 6.4. (An upgrade for Java 6 is on the cards, but not before go-live date.) We have pentest fails for a weak ...
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0answers
188 views

How to import Comodo certificates into Keystore?

I'm trying to create a Keystore. I've already generated a Private Key, generated and sent a certificate request to a CA (Comodo), and I've received a ZIP file from the CA (Comodo) containing four ...
5
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1answer
137 views

Dynamically decrypting files

Is it possible to store (video) files encrypted (using AES or similar) in the cloud and have clients' browsers download those files and dynamically decrypt them to start viewing them whilst they are ...
2
votes
1answer
125 views

Chrome/FF not negotiating advanced ciphers?

Ran into a weird problem trying to lock down our AWS ELBs today, specifically trying to deprecate all support for SHA-1. Having removed options like AES256-SHA ECDHE-RSA-AES256-SHA (among others) ...
4
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2answers
3k views

TLS_RSA_WITH_3DES_EDE_CBC_SHA reported as 112 bits

I am no expert in this area but after some searching I am not too sure about the solution. An external vendor doing a pentration test on our server reported that we have ...
1
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2answers
102 views

Dovecot TLS connection handshake ChangeCipherSpec

I added a virtual domain to our mail server today then did a check of the Dovecot TLS connection security. The test was done from a remote host using Thunderbird. I captured the connection with ...
2
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0answers
116 views

Deciphering “easy” ciphers without hints [closed]

I've been keen on IT Security for a long time now and I've learned a lot about networking & security. However trying a "decryption challenge" I'm lacking what I think is basic encryption/...
0
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2answers
1k views

Meaning of mod_ssl cipher suite put together and order of preference

I read cipher suite description of mod_ssl, and understood the meaning of alias and keywords like ! + etc. But I am unable to understand how to read ALL:!ADH:!EXPORT:!SSLv2:RC4+RSA:+HIGH:+MEDIUM:+LOW ...
0
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2answers
123 views

Encryption in case of distributed architecture

I have application infrastructure as follows - web client -> load balancer -> Apache (web server) -> Weblogic (application server). I could understand that in case of HTTPS request, SSL handshake ...
2
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1answer
621 views

Setting node.js TLS ciphers vs observed behavior

I have a node.js server that I'm configuring for TLS 1.2. I set the following options in the config of my https server: ciphers: 'ECDHE-ECDSA-AES256-SHA384:ECDHE-RSA-AES128-SHA256:DHE-RSA-AES128-...
3
votes
3answers
327 views

Cipher used for request data encryption used by browser

Please note that this is not about how SSL communication happens between browser (I researched and understood it) and client but other aspects. Using Digicert's SSL mechanism explanation I have ...
3
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3answers
2k views

How do browsers negotiate SSL/TLS connection parameters?

For the purpose of this question, let assume that an SSL/TLS connection has 4 parameters: protocol, symmetric encryption method, asymmetric encryption method, MAC. During the negotiation of SSL ...
2
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2answers
141 views

Secure communication in SHTF

I am a prepper. I am preparing for a situation where there will be no rule of law and where I can't rely on the government for all my needs. This naturally involves storing food, water, and items for ...
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0answers
80 views

Are there any tools out there that can 'trick' keyloggers?

Are there any tools out there that can 'trick' keyloggers? I was wondering if there's any 'enigma-style' tools available along the lines of providing time-randomised keyboard mappings. For example: ...
3
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3answers
4k views

How to pass cipher list to OpenSSL s_client

How we can pass a cipher list to the OpenSSL s_client program? We can pass single cipher by this: openssl s_client -cipher 'ECDHE-RSA-AES256-SHA' -connect www.google.com:443 But how to pass a list ...
1
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1answer
274 views

What's RSA and ECC's role in TLS 1.2? [duplicate]

I'm trying to figure out what is RSA and ECC used for in TLS 1.2 cipher suites. Let's take TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305_SHA256 for example, communication between server and client would look ...
2
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2answers
328 views

Openssl ciphers: what does Au=ECDH mean?

I am trying to get a grasp on different stages of SSL. I have referred to some fantastic answers about how SSL/TLS works and specifically about authentication mechanisms, and numerous other sources. ...
3
votes
1answer
603 views

Is CVE-2013-2566 a practical attack against RC4 or still conceptual?

Is CVE-2013-2566 a practical attack against RC4 or still conceptual and does it only apply to WPA/TKIP?
1
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1answer
315 views

How to change personal cipher/digest preferences of existing OpenPGP key in GnuPG?

The OpenPGP key contains a list of personal algorithm preferences (the meaning of the numbers can be decoded in RFC 4880): # gpg -a --export "foo@example.com" | gpg --list-packets | fgrep 'pref-' ...
0
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1answer
449 views

Google Chrome obsolete cryptography

I have a apache server running and following configuration for ssl: Header always set Strict-Transport-Security "max-age=31536000; includeSubDomains" SSLProtocol -all +TLSv1.2 SSLCompression Off ...
3
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0answers
383 views

OpenSSL: Allow CBC ciphers for TLS but prevent for SSL3

In my server application using OpenSSL, to prevent the poodle attack, I added an option to fully allow/prevent SSL3 protocol. SSL_CTX_set_options(ctx, SSL_OP_NO_SSLv2); //Prevent SSLv2 ...
1
vote
1answer
226 views

Choosing a cipher and MAC for an SSH connection

The cipher and mac selection according to this are in some sort of order in a config file. How do the client and server know that they are using the same ones though? Is this information exchanged in ...
4
votes
1answer
1k views

DHE_DSS vs. DHE_RSA

I have been studying to learn about various cipher suites and their performance; I'm wondering about the difference between DHE_DSS_AES256_CBC ciphersuites and DHE_RSA_AES256_CBC ciphersuites. I ...
3
votes
1answer
4k views

Creating a private key with OpenSSL and encrypting it with AES GCM

My goal was to create a private key and to encrypt it with a strong cipher. That key would be used as a root certificate for an internal Certification Authority. However, eventhough openssl supports ...