Summary
The consensus is that 2048-bit DKIM keys offer stronger security compared to 1024-bit keys, making them harder to crack and forge. While 1024-bit keys are still supported and may be acceptable for some use cases, 2048-bit keys are increasingly recommended as the industry standard for enhanced security and future-proofing. However, potential drawbacks include compatibility issues with older MTAs and DNS systems, as well as difficulties in managing longer DNS TXT records. Experts recommend considering organizational needs, security requirements, and potential infrastructure limitations before making a decision.
Key findings
- Enhanced Security: 2048-bit keys provide significantly stronger encryption, making them harder to crack and reducing the risk of email spoofing.
- Industry Standard: 2048-bit keys are becoming the industry standard and are recommended for long-term security.
- Functionality of 1024-bit Keys: 1024-bit keys may still function adequately, but they offer less protection against modern threats.
Key considerations
- Compatibility: Older MTAs and DNS systems may experience compatibility issues with 2048-bit keys.
- DNS Management: Managing longer 2048-bit DKIM records can be challenging due to DNS TXT record size limitations, potentially requiring record splitting or alternative DNS management methods.
- Organizational Requirements: Organizations handling sensitive data or subject to strict regulatory requirements may need to prioritize the enhanced security of 2048-bit keys.
- Effort vs. Benefit: Consider the effort required to implement 2048-bit keys against the incremental security benefit, especially if existing systems are already secure and regularly monitored.
What email marketers say
14 marketer opinions
The primary advantage of a 2048-bit DKIM key over a 1024-bit key is enhanced security due to the increased difficulty in cracking or forging signatures. While 1024-bit keys may still be functional and compliant with some standards, they are increasingly considered less secure and may not offer sufficient protection against sophisticated attacks. However, potential drawbacks of 2048-bit keys include compatibility issues with older mail transfer agents (MTAs) or DNS systems, as well as challenges in managing longer DNS TXT records.
Key opinions
- Security: 2048-bit keys offer significantly stronger encryption and are more resistant to cracking or forging compared to 1024-bit keys.
- Industry Standard: 2048-bit keys are increasingly becoming the industry standard and are recommended for future-proofing security measures.
- Vulnerability: 1024-bit keys are more vulnerable and easier to crack.
- Mitigation: Using 2048 keys can better protect from email spoofing.
Key considerations
- Compatibility: Older MTAs and DNS systems might have compatibility issues with 2048-bit keys.
- DNS Management: Longer 2048-bit keys can pose challenges in DNS management due to TXT record size limitations, potentially requiring record splitting.
- Compliance: While 1024-bit keys may still be acceptable, some regulations or security requirements may necessitate the use of 2048-bit keys.
- Organizational Need: Military, government, or financial institutions may require more secure 2048-bit keys.
Marketer view
Marketer from Email Geeks shares that 1024-bit keys are still okay unless you work in military-related fields.
5 Sep 2021 - Email Geeks
Marketer view
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.
2 Apr 2024 - StackExchange
What the experts say
7 expert opinions
Experts suggest that while 1024-bit keys might still be functional and acceptable, 2048-bit keys offer better security and future-proofing against increasingly sophisticated attacks. Operationally, the difference may not be significant for most users. However, managing 2048-bit keys can be challenging with some DNS management interfaces, and older systems might not support them. A key motivator for upgrading to 2048-bit is often to meet security best practices and avoid criticism, not necessarily because 1024-bit is immediately vulnerable.
Key opinions
- Enhanced Security: 2048-bit keys offer better security due to the increased difficulty in forging signatures and future-proofing.
- Operational Similarity: Operationally, there isn't a huge difference between 1024 and 2048 bit keys for most use cases.
- Limited Compatibility Concerns: Most mailservers should be able to handle 2048 bit keys.
Key considerations
- DNS Management Issues: Managing 2048-bit keys in DNS can be problematic, especially with low-end web interfaces, potentially requiring record splitting.
- Legacy System Support: Consider compatibility with older MTAs when implementing 2048-bit keys.
- Security Consultant Scrutiny: Upgrading to 2048-bit keys can preempt criticism and satisfy security best practices, even if 1024-bit is currently sufficient.
Expert view
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.
18 Apr 2024 - Email Geeks
Expert view
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.
29 Mar 2024 - Email Geeks
What the documentation says
4 technical articles
Documentation consistently points to 2048-bit DKIM keys offering enhanced security compared to 1024-bit keys. While 1024-bit keys are supported, 2048-bit or greater keys are recommended for better protection against attacks.
Key findings
- Stronger Security: 2048-bit DKIM keys are more secure and harder to crack than 1024-bit keys.
- Recommendation: Industry documentation recommends using 2048-bit DKIM keys for better security.
- Vulnerability: 1024-bit keys provide a lower level of protection against attacks.
Key considerations
- Support: 1024-bit keys must be supported; however, 2048 is still the recommendation.
Technical article
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.
16 Oct 2024 - Google
Technical article
Documentation from Cloudflare explains that a 2048 bit key is stronger and recommended over 1024 bit.
13 Feb 2024 - Cloudflare
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