Editing Portal:Crypto and Blockchain (section)

=== Cryptography: the older meaning of “crypto” ===

Before “crypto” became common shorthand for cryptocurrency, it meant cryptography. Perl already had a substantial cryptographic ecosystem before Bitcoin became popular. Bitcoin and similar systems depend on cryptographic hash functions, elliptic-curve signatures, binary encodings, checksums, and secure random numbers.

Perl’s `Digest::SHA` module provides SHA-family hashing, including SHA-256.<ref>MetaCPAN, “Digest::SHA,” https://metacpan.org/pod/Digest::SHA, accessed July 3, 2026.</ref> Bitcoin uses SHA-256 heavily, including double-SHA-256 hashing in block and transaction identifiers. Perl’s `Crypt::RIPEMD160` module provides RIPEMD-160 hashing, another algorithm historically used in Bitcoin address construction.<ref>MetaCPAN, “Crypt::RIPEMD160,” https://metacpan.org/pod/Crypt::RIPEMD160, accessed July 3, 2026.</ref>

Perl also has broader cryptographic toolkits. `CryptX` is a Perl cryptographic toolkit built on LibTomCrypt and LibTomMath.<ref>MetaCPAN, “CryptX,” https://metacpan.org/pod/CryptX, accessed July 3, 2026.</ref> `Crypt::PK::ECC` provides elliptic-curve cryptography functions including ECDSA and ECDH.<ref>MetaCPAN, “Crypt::PK::ECC,” https://metacpan.org/pod/Crypt::PK::ECC, accessed July 3, 2026.</ref> These capabilities matter because Bitcoin-style systems rely on elliptic-curve keys and signatures.

Bitcoin also popularized encodings such as Base58Check, which avoid visually confusing characters and are used in human-facing addresses. Debian describes `Encode::Base58` as a Perl module for Base58 encoding and notes that Base58 is used in Bitcoin addresses.<ref>Debian Packages, “libencode-base58-perl,” https://packages.debian.org/trixie/libencode-base58-perl, accessed July 3, 2026.</ref>