What does the hash algorithm (digest) mean for CSR generation?

A hash algorithm is a mathematical function that is used to transform data into a fixed, irreversible character string, also known as a "hash value" or "digest". This value is unique for the data entered and even the smallest changes to the data result in a completely different hash value. In CSR generation, the hash algorithm determines how the checksums are created that systems use to verify that the certificate and signatures are valid and that the data has not been tampered with in transit.

Which hash algorithms are used for CSR generation?

There are several hash algorithms that can be used in CSR generation. Here are some of the most important ones:

• MD4 (Message Digest 4)

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  MD4 generates a 128-bit hash value. It used to be used in security protocols but is outdated due to security concerns and should be avoided.
• MD5 (Message Digest 5)

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  MD5 also generates a 128-bit hash value. It was widely used in the past but is now insecure due to collisions where two different sets of data can generate the same hash value.
• RIPEMD 160 bit

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  RIPEMD (RACE Integrity Primitives Evaluation Message Digest) generates a 160-bit hash value. It was developed to circumvent the weaknesses of MD4 and MD5.
• SHA-1 (Secure Hash Algorithm 1)

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  SHA-1 generates a 160-bit hash value. SHA-1 is now also considered insecure due to collisions and experts recommend the use of stronger algorithms.
• SHA-2 (Secure Hash Algorithm 2)

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  SHA-2 consists of several variants with different bit lengths, including SHA-2 512 bit, SHA-2 384 bit, SHA-2 256 bit and SHA-2 224 bit. These variants offer a higher level of security compared to their predecessors.
• SHA-3 (Secure Hash Algorithm 3)

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  SHA-3 is the latest standard and also offers different variants, including SHA-3 512 bit, SHA-3 384 bit, SHA-3 256 bit and SHA-3 224 bit. SHA-3 is based on a different construction method and offers an alternative to SHA-2.

Which hash algorithm should I choose for CSR generation?

It is strongly recommended to avoid outdated algorithms such as MD4, MD5 and SHA-1. For optimal security, SHA-2 or SHA-3 should be preferred, depending on the requirements and the support of the software used.

Is there anything else to consider?

Yes, the choice of hash algorithm should be in line with current security standards and recommendations in the industry. It is advisable to follow the latest developments and recommendations, as security technologies are subject to constant change.