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Is there support for RC4 encryption in Thunderbird?

  • 1 reply
  • 1 has this problem
  • 4 views
  • Last reply by Matt

We use software called RealEC and received the warning message below.

Can you tell from this whether it is possible that this provider's dropping of RC4 ciphers is going to affect anything when we get messages from them in Thunderbird?

Thank you!

Here's the notification we received:

Dear Valued Client,

RealEC will no longer support RC4 ciphers as of 12/9/2016.

Rationale For This Action Based on BKFS security standards and consensus in the security industry, support for RC4 ciphers is being removed. The RC4 cipher can be broken within hours or days and typical attacks on RC4 exploit biases in the RC4 keystream to recover encrypted plaintexts.

What You Should Do To prevent any disruption to your business when support for RC4 ciphers is removed, please work with your email support group to ensure that outbound and inbound email processing with RealEC Technologies no longer uses RC4 ciphers. If you continue to use RC4 ciphers after 12/9/2016, your email processing with RealEC will be disrupted.

Change Schedule Dates
Environment

Sites Planned Implementation Date RealEC Email Application Jtcmail.realec.com 12/9/2016 RealEC Email Application Jtcmail2.realec.com 12/9/2016

Please ensure that your email support group receives this information to take the necessary steps to minimize any business impacts that these changes may have to your operations.
We use software called RealEC and received the warning message below. Can you tell from this whether it is possible that this provider's dropping of RC4 ciphers is going to affect anything when we get messages from them in Thunderbird? Thank you! Here's the notification we received: Dear Valued Client, RealEC will no longer support RC4 ciphers as of 12/9/2016. Rationale For This Action Based on BKFS security standards and consensus in the security industry, support for RC4 ciphers is being removed. The RC4 cipher can be broken within hours or days and typical attacks on RC4 exploit biases in the RC4 keystream to recover encrypted plaintexts. What You Should Do To prevent any disruption to your business when support for RC4 ciphers is removed, please work with your email support group to ensure that outbound and inbound email processing with RealEC Technologies no longer uses RC4 ciphers. If you continue to use RC4 ciphers after 12/9/2016, your email processing with RealEC will be disrupted. Change Schedule Dates Environment Sites Planned Implementation Date RealEC Email Application Jtcmail.realec.com 12/9/2016 RealEC Email Application Jtcmail2.realec.com 12/9/2016 Please ensure that your email support group receives this information to take the necessary steps to minimize any business impacts that these changes may have to your operations.

Chosen solution

RC4 was disabled in Firefox with the Firefox 44 release. As Thunderbird and firefox share source code at that level, then the RC4 cypher will be disabled in all of the Thunderbird 45 releases.

So if you have no issues and are using Thunderbird 45 it means nothing to you at all.

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All Replies (1)

Chosen Solution

RC4 was disabled in Firefox with the Firefox 44 release. As Thunderbird and firefox share source code at that level, then the RC4 cypher will be disabled in all of the Thunderbird 45 releases.

So if you have no issues and are using Thunderbird 45 it means nothing to you at all.