Bitcoin Address (Legacy)

Name: Bitcoin Address (Legacy)
Creator: TestPattern Community
License: https://opensource.org/licenses/MIT

Detects Bitcoin Address (Legacy) patterns.

Type: regex
Engine: universal
Confidence: medium
Confidence justification: Medium confidence: pattern has structural constraints but corroborative keywords are recommended to reduce false positive rates. Added context gating and exclusion rules improve precision and reduce incidental matches.
Detection quality: Verified
Jurisdictions: global
Frameworks: ISO 27001, ISO 27701, PCI-DSS, SOC 2
Data categories: financial
Scope: narrow
Platform compatibility: Purview: Compatible, GCP DLP: Compatible, Macie: Compatible, Zscaler: Compatible, Palo Alto: Compatible, Netskope: Compatible

Pattern

\b[13][a-km-zA-HJ-NP-Z1-9]{24,33}\b

Corroborative evidence keywords

identifier, number, ID, transaction, transfer, payment, deposit, withdrawal, debit, credit, field, column, row, entry, record, value, form, register, database, extract (+16 more)

Proximity: 300 characters

Should match

1A1zP1eP5QGefi2DMPTfTL5SLmv7DivfNa — Bitcoin legacy address starting with 1
3J98t1WpEZ73CNmQviecrnyiWrnqRhWNLy — Bitcoin P2SH address starting with 3
1BvBMSEYstWetqTFn5Au4m4GFg7xJaNVN2 — Standard Bitcoin address

Should not match

2A1zP1eP5QGefi2DMPTfTL5SLmv7DivfNa — Invalid first character (2 instead of 1 or 3)
1A1zP1eP5QGefi2DMPTf — Too short (only 20 characters)
1A1zP1eP5QGefi2DMPTOL5SLmv7DivfNa — Contains invalid character O (excluded from base58)
template example placeholder record identifier — Template/sample context should be excluded even when anchor words are present

Known false positives

Financial terminology appearing in published reports, accounting textbooks, regulatory guidance, or template documents without actual transaction data. Mitigation: Require corroborative evidence keywords within the proximity window. Cross-reference with structured financial identifiers to confirm actual sensitive data.
In English (as the primary international business language), standard business terminology overlapping with financial detection keywords in routine correspondence and documentation. Mitigation: Increase confidence threshold when scanning business correspondence. Layer with transaction-specific patterns for higher precision.

Collections

Cryptocurrency Wallet Addresses