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1answer
59 views

How are TLSv1.0 ciphers negotiated as TLSv1.2?

I'm a little confused about something I am reading in Bulletproof SSL. "TLS 1.2 is the only protocol that allows suites to define their PRFs. This means that for the suites defined before TLS 1.2 ...
1
vote
1answer
46 views

ECDSA/RSA certifcates and cipher selection

In this image can someone tell me if a standard RSA certificate can support the EC*_RSA ciphers listed? If so do you create the typical RSA keys when you are creating the CSR? Also I am fairly ...
2
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1answer
56 views

Drawbacks to only using TLS 1.2 ciphers in OpenSSL

I understand you would not want to do this as it would limit compatibility for older devices and platforms. However if someone were in an all TLS1.2 environment, say a very well managed internal ...
1
vote
1answer
49 views

Display browser requested cipher suites from OpenSSL

I installed OpenSSL locally and used s_server command to start a server by using self signed certificate created by OpenSSL as well. The command I used to start a https server is OpenSSL> s_server ...
1
vote
1answer
177 views

Using AES as a Stream Cipher

I need to send a lot of small messages that are usually between 128 bits and 256 bits long, and each message is encrypted with a separate 128 bit AES key. Therefore, to send each message with the key ...
4
votes
1answer
122 views

How did SSLv3 get AES?

IANA maintains a registry of TLS cipher suites at TLS Parameters. TLS provides TLS_RSA_WITH_AES_128_CBC_SHA, its value is {0x00, 0x2f}, and its available in TLS 1.0 and above. The AES cipher suites ...
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0answers
42 views

BKSQ block cipher

I'm trying to implement the BKSQ block cipher (similar to AES) but to do so I need the inverse mixcolumns operation, therefor I need to inverse the 2x^2+2x+3 operation. e.g for the AES it is c(x) = ...
0
votes
2answers
99 views

How secure would this method be considered for password storage

Ok I am currently storing the passwords in most secure way I could think of. With use of Encryption and Hash. The passwords are first generated by user as plain-text with minimum length of 6 ...
0
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1answer
117 views

Openssl ciphers SHA384 and AEAD

When running the command: openssl ciphers -v I get a long list of cipher combinations. I'm having issues interpreting some of them. An example is: DHE-RSA-AES256-GCM-SHA384 TLSv1.2 Kx=DH Au=RSA ...
1
vote
3answers
108 views

Is it possible to stack encryption algorithms with SSL?

SSL supports a number of ciphers, but is it possible to stack/nest the ciphers, and process the plaintext in stages? My adversary may be able to easily crack one or more of the stages, but to decode ...
1
vote
1answer
136 views

What is default mode for AES encryption [closed]

What will be the default mode for AES encryption if we don't use any specific mode like ECB, CBC, OFB, CTR, etc. and just carry out the encryption without specifying any AES encryption mode.
0
votes
1answer
670 views

Which is the Best Cipher Mode and Padding Mode for AES Encryption? [closed]

As per PCI-DSS 3.4 requirement: For storing Credit Card Data Strong Cryptography should be used. I decided to use AES Encryption which is a strong and mostly recommended crypto for encrypting ...
0
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0answers
21 views

What SSL/TLS ciphers do each version of Android support? [duplicate]

What ciphers do each Android device support? Update: More specific not SSL or TLS versions but the actual ciphers such as ECDHE-ECDSA-AES128-GCM-SHA256, etc. Android 2.3? Android 3.x? Android ...
25
votes
3answers
10k views

“Optimal” Web Server SSL Cipher Suite Configuration

Over the last couple of years there have been a number of changes in what would be considered an optimal SSL cipher suite configuration (e.g. the BEAST and CRIME attacks, the weaknesses in RC4) My ...
1
vote
1answer
104 views

Block Cipher Pseudocode

Suppose that I have a block cipher whose key size is 128 bits. but the block length is eight bits. Let E(m’) be an encryption oracle that encrypts by running our “short” block cipher in CBC mode. ...
1
vote
1answer
163 views

Why does not GSM use any stream cipher mode (OFB, CFB)?

If I understand correctly GSM uses A5/1 stream cipher. My question is why doesn't it use a stream cipher mode like OFB or CFB?
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votes
2answers
459 views

Forward secrecy for kids

In the Scouts, it is popular to use secret codes to write messages (which are simple ciphers). I want to introduce Forward secrecy to the kids so they can use it with these ciphers. So, if the ...
4
votes
2answers
5k views

Identify and disable weak cipher suites

i'm asking a question on a subject that is pure chinese to me..sorry in advance A security scan result prior to the deployment of a web application on windows server 2008 R2 has raised the below ...
3
votes
1answer
162 views

Are all cipher suites with rc4 in them intrinsically flawed?

I've been wondering lately if RC4 is so flawed in all its forms, why is it that it is still being supported by all major browsers per default? Why does the typical chrome browser prefer ...
2
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2answers
199 views

For DHE_RSA_.. Cipher Suites what is RSA used for?

In addition to achieving PFS with DHE, we want as little as possible to be revealed when the server's private key is revealed. So, what is RSA used for in DHE_RSA cipher suites? What does the server ...
2
votes
1answer
3k views

TLS v1.0 best cipher for OpenVPN setup

I'm trying to setup OpenVPN with as much security as I can. I'm in the process of selecting a cipher for OpenVPN. Which is the safest one, tls-cipher DHE-RSA-AES256-SHA or tls-cipher AES256-SHA? I've ...
1
vote
1answer
192 views

Export ciphers prevalance

I would like to clarify the consequences of not supporting export ciphers. When I run a qualys ssl test on ebay.com, I notice that the following cipher suites are supported. ...
0
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1answer
1k views

“Must have” and “Preferred Cipher” suites terminology

I have received the following advise to set cipher suites to suitably mitigate Beast attack on a newly setup Apache HTTPD server. Preferred ciphers: RC4-SHA, RC4-MD5 Must Have Ciphers: ...
4
votes
1answer
424 views

Is possible that a TLS server send more than one certificate to the client for the same site?

What I'm trying to archive is enable ECDSA and DSS ciphers in my site, but at the same time not depend just of self signed certificates, so I could sent to my client more than one certificate and them ...
3
votes
1answer
849 views

What could be the order of these ciphers following as first criteria the security and just then the performance?

I need some guide to decide in which order I must put the following ciphers if I want prioritize security and in cases of tied, consider performance to decide. ECDHE-RSA-AES256-GCM-SHA384 TLSv1.2 ...
5
votes
1answer
2k views

What block ciphers and algorithms are now safe? [closed]

I work for a large non-US based international organisation. Regarding the recent leaks about the NSA breaking most encryption on the internet, we now know the US and UK governments are actively ...
2
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1answer
580 views

Configuring GCM cipher suites in Jetty based server

I have a Jetty based secure http service, and I wish to support GCM cipher suites. I know that Jetty internally use JSSE based ciphers, and there are many GCM ciphers coming with JSSE as documented ...
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3answers
2k views

Hardened SSL ciphers for Nginx as AWS/Cloudfront Custom Origin

Based on recommendations, we recently attempted to harden our Nginx SSL configuration against BEAST/CRIME/BREACH attacks with the following stanza: ssl_prefer_server_ciphers on; ssl_ciphers ...
0
votes
1answer
256 views

How to get an exhaustive list of ciphers for TLS 1.0, TLS 1.1 and TLS 1.2

After TLS 1.0, there have been a number of RFCs e.g RFC 5932, RFC 6430 etc. Is there any place where one can get an exhaustive list of ciphers for each of the versions. Or at least an exhaustive list ...
3
votes
1answer
3k views

Is using RC4-MD5/RC4-SHA as SSL ciphers enough for most purpose?

In the AWS ELB, I have uploaded a cert and only selected "RC4-MD5" + "RC4-SHA" as the ciphers and scored A in the ssltest [1] If I using the default ELB setting, I can only score a C Since I am not ...
3
votes
3answers
3k views

Disabling SSL v2 and weak ciphers on client PC's

Is it a requirement to also disable SSL v2 and weak ciphers on client PC's? I have seen quite a few posts for disabling them on servers, but nothing about a regular client PC, say, running Windows XP ...
1
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2answers
229 views

Recommended authenticated stream cipher for minimum overhead?

I'm running my TCP/IP protocol secured by encrypting each packet with AES128/CBC, bundling a SHA256 HMAC over that packet. This causes quite a bit of space overhead for small packets, so at first I ...
5
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1answer
370 views

Known plaintext; What cipher is being used here? [closed]

plaintext: CANDY VERY CRANBERRY ciphertext: TXOtWjYhVk 8&O$4AmSA plaintext: http ciphertext: cZf. plaintext: http ciphertext: r5Hz This is definitely somehow decodable from ...
21
votes
1answer
4k views

TLS: RC4 or not RC4?

I was reading another interesting article by Matthew Green today, saying that if you're using RC4 as your primary ciphersuite in SSL/TLS, now would be a great time to stop As far as I'm aware ...
10
votes
1answer
4k views

Is AES-GCM recommended for SSL?

I'm looking at turning on site-wide SSL for a website I manage, and I'm wondering what the best practices for SSL configuration. I'm not too worried about compatibility with old browsers and more ...
1
vote
1answer
100 views

Ciphertext for email vs Ciphertext for database

Let's say Bob wants to send a message to Alice. This communication requires to achieve confidentiality, integrity, proof of origin, non-repudiation. Therefore we can use this cipher-text: ciphertext ...
7
votes
1answer
5k views

What are the differences between the arcfour, arcfour128 and arcfour256 ciphers in OpenSSH?

What are the differences between the arcfour, arcfour128 and arcfour256 ciphers in OpenSSH? I am interested about: speed and security implications. I know that arcfour is fast for file transfers, ...
4
votes
2answers
17k views

OpenSSH default/preferred ciphers, hash, etc for SSH2

When using OpenSSH server (sshd) and client (ssh), what are all of the default / program preferred ciphers, hash, etc. (security related) and their default options (such as key length)? So, what are ...
156
votes
8answers
66k views

Why not use larger cipher keys?

RSA Security commonly uses keys of sizes 1024-bit, 2048-bit or even 3072-bit. And most Symmetric algorithms only between 112-bit and 256-bit. I do realize that the current keys are secure enough for ...
4
votes
1answer
836 views

IIS 6.0 - mitigating BEAST

Recently, my PCI assessor informed me that my servers are vulnerable to BEAST and failed me. I did my homework and I want to change our webservers to prefer RC4 ciphers over CBC. I followed every ...
4
votes
2answers
552 views

Block cipher Implementation in C++

I'm writing an implementation of a block cipher in C++. I would like to study differential cryptanalysis of the cipher, so I'm generating random plaintexts and keys and then encrypt them. Which is ...
1
vote
1answer
630 views

How does Cipher Block Chaining relate to AES?

I was reading FIPS197 for a class (found here: http://csrc.nist.gov/publications/fips/fips197/fips-197.pdf ) trying to find some sort of specific relation between CBC and AES. I guess my problem is ...
4
votes
2answers
696 views

Picking cipher suites for HTTPS

I'm trying to work out the best approach to choosing which cipher suites to provide, and what the issues might be. It's my understanding that during the SSL handshake, the client will (normally) ...