How deeply does Real-World Cryptography cover sponge construction?

Works through rate-capacity division, single-block absorption, repeated absorption, and digest extraction, but defers keccak-f design.

Sponge construction

As explained in Real-World Cryptography

A sponge construction repeatedly applies a permutation while absorbing input through a rate portion of its state and producing output through that portion.

A sponge construction turns a fixed permutation into a hash-like process. It divides the permutation state into a rate and a capacity, absorbs input through the rate, and later squeezes output from it. section 2.5.2

A small sponge

With an 8-bit permutation and a 5-bit rate, absorbing 00101 means XORing those five bits into a rate initialized to zero, then permuting the complete state.

How Real-World Cryptography covers it

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Related concepts

Merkle–Damgård constructioncontrasts with · The Merkle–Damgård construction builds an arbitrary-length hash function by iteratively applying a fixed-size compression function to padded message blocks.
SHA-3implemented by · SHA-3 is a NIST-standardized family of cryptographic hash functions based on the Keccak sponge construction and providing multiple fixed-length output sizes.
length-extension attackcontrasts with · A length-extension attack exploits an iterative hash construction to compute a hash for an extended message from the original hash and message length.
absorbinghas part · Absorbing is the phase of a sponge construction in which input blocks are incorporated into its internal state and permuted.
cryptographic constructionkind of · A cryptographic construction is a concrete algorithm or protocol that instantiates one or more cryptographic concepts or primitives.

This explainer was generated by Manning's knowledge graph from the text of Real-World Cryptography. The section links point to the parts of the book it draws on.