What are the pros and cons of 1024-bit vs 2048-bit DKIM keys?
Summary
What email marketers say14Marketer opinions
Marketer from Email Geeks shares that 1024-bit keys are still okay unless you work in military-related fields.
Email marketer from StackExchange explains that 2048-bit keys are longer, which makes them more secure and harder to crack. However, some older systems or DNS providers might have issues with the increased length of the key, especially when manually configuring DNS records.
Email marketer from StackOverflow explains that DNS TXT record size limitation can cause issues with 2048 bit key deployment in some situations, and splitting the record is required.
Email marketer from EasyDMARC shares that using a 2048-bit DKIM key is recommended for enhanced security. They explain that while 1024-bit keys are still functional, they are more vulnerable to being cracked compared to the stronger 2048-bit keys, which offer a higher level of encryption and protection.
Email marketer from StackExchange notes that while 2048 is better, some older systems might struggle. He also mentions potential issues with pasting long records into DNS management tools.
Email marketer from Reddit explains that transitioning to 2048-bit DKIM keys is a good security practice. They recommend rotating DKIM keys periodically and using 2048-bit keys for better protection against email spoofing.
Email marketer from Reddit shares that a 2048-bit key is better because a 1024-bit key is easier to crack. The longer the key, the more computationally expensive it is to forge a signature.
Marketer from Email Geeks reports no deliverability loss since switching to a 2048-bit key and are pushing forward with global implementation for all clients.
Email marketer from StackExchange explains that the cost of using 2048 bits is almost negligible, and the advantage of the higher encryption is significant. Given current computing capabilities, 1024 bit may be considered unacceptably weak in some circles now.
Email marketer from Mailhardener states that 2048 bit keys are more secure than 1024-bit keys. They state that 2048 bit keys are recommended to avoid potential issues and increase the longevity of the keys. They also state that while 1024 bit keys are accepted the industry standard is now 2048-bit keys.
Marketer from Email Geeks notes that the RFC for DKIM still says 1024-bit is acceptable for marketing email. 2048-bit is better for government or financial institutions. Older MTAs may have issues with 2048-bit keys.
Marketer from Email Geeks explains that the difference between 1024-bit and 2048-bit keys is the length of the key, and longer keys are harder to crack.
Email marketer from MXToolbox says that while some providers may allow 1024 bit key, 2048 bit is more secure and the recommended key length to use.
Email marketer from RPGPGM.COM explains that the longer the DKIM key is, the harder it is to forge signatures. A 2048-bit key is significantly more secure than 1024-bit but older versions of IBM iSeries might not support it.
What the experts say7Expert opinions
Expert from Email Geeks shares that using a 2048-bit key can be painful if you manage DNS yourself via your domain registrar portal, as it may not fit and require splitting.
Expert from Email Geeks explains that while a 1024-bit key is currently fine against reasonably funded attackers, the main reason to use 2048-bit keys is to avoid criticism from security consultants.
Expert from Email Geeks says that operationally, there isn't much difference between 1024 and 2048 bit DKIM keys and that 2048 is fine.
Expert from Email Geeks shares they would be surprised if any noticeable number of mailservers failed to handle a 2048 bit key as they see them used a lot, including mainstream ecommerce sites.
Expert from Spam Resource shares that longer keys are more difficult to forge signatures. Therefore, using 2048 bit is safer than 1024. However, Spam Resource doesn't seem to explicitly weigh the pros and cons of each key.
Expert from Word to the Wise suggests using 2048-bit keys because they are more secure, even though 1024-bit keys may still be accepted by some providers. It's about future-proofing and making sure that your keys aren't easily cracked. However, you must consider if you have legacy MTAs still in use.
Expert from Email Geeks explains that 2048-bit keys implementation is riddled with bugs and crappy implementation in low-end DNS management web interfaces.
What the documentation says4Technical articles
Documentation from Google explains that a 2048-bit key provides more security than a 1024-bit key. In the Admin console you can generate a DKIM key with a bit length of 1024 bits or 2048 bits. A 2048-bit key is more secure than a 1024-bit key.
Documentation from Cloudflare explains that a 2048 bit key is stronger and recommended over 1024 bit.
Documentation from ietf.org (RFC 6376) specifies that while key sizes of 1024 bits MUST be supported, key sizes of 2048 bits or greater are RECOMMENDED.
Documentation from DigiCert explains that using a 2048-bit DKIM key is more secure than a 1024-bit key because it is significantly more difficult to crack. Although 1024-bit keys may still be functional, they do not offer the same level of protection against sophisticated attacks. They recommend 2048-bit DKIM keys.