CryptoJS
JavaScript cryptographic standards library. Implements AES, DES, 3DES, Rabbit, RC4 encryption, plus HMAC, SHA-1, SHA-256, SHA-512, MD5, and PBKDF2 hash/KDF functions. Works in browser without native dependencies. Historically popular for client-side cryptography when the Web Crypto API didn't exist. NOTE: CryptoJS is now largely superseded by the native Web Crypto API (available in all modern browsers and Node.js 15+) which is faster and more secure.
Score Breakdown
⚙ Agent Friendliness
🔒 Security
CryptoJS has known timing attack vulnerabilities and is not regularly audited. Decryption silently fails. Weak key derivation defaults. Use native crypto APIs for new code.
⚡ Reliability
Best When
You have an existing codebase using CryptoJS or need symmetric encryption in a legacy browser environment where Web Crypto is unavailable.
Avoid When
Building new applications on modern Node.js or modern browsers — use native crypto APIs instead. CryptoJS is a legacy choice.
Use Cases
- • Hash strings with SHA-256 or HMAC-SHA256 in environments without native crypto API support
- • AES encryption/decryption in browser applications where Web Crypto API is unavailable or inconvenient
- • Generate HMAC signatures for message authentication in JavaScript applications
- • Compute MD5 hashes for checksums or data fingerprinting (not for security purposes)
- • Support legacy browser cryptography requirements in applications targeting older browsers
Not For
- • Modern Node.js applications — use Node.js built-in crypto module instead; it's faster and maintained by Node core team
- • Modern browser applications — use native Web Crypto API (window.crypto.subtle); it's hardware-accelerated and time-constant
- • Password hashing — never use CryptoJS (or any fast hash) for passwords; use bcrypt, scrypt, or Argon2
Interface
Authentication
No authentication — cryptography utility library.
Pricing
Fully free, MIT licensed.
Agent Metadata
Known Gotchas
- ⚠ CryptoJS is NOT maintained with regular security updates — use native Web Crypto API or Node.js crypto for new code; CryptoJS has known timing attack vulnerabilities
- ⚠ Decryption failures return empty string, not an error — must validate decrypted output; silently wrong decryption is a common source of hard-to-debug issues
- ⚠ AES without explicit IV uses a random salt approach that's incompatible with other libraries — always specify explicit IV for cross-platform AES compatibility
- ⚠ Key derivation from passphrase uses MD5-based OpenSSL EVP_BytesToKey which is weak — use PBKDF2 with high iterations for password-derived keys
- ⚠ Output format: CryptoJS uses its own WordArray object — must call .toString() or .toString(CryptoJS.enc.Base64) to get a usable string output
- ⚠ SHA-1 and MD5 are cryptographically broken — use only for checksums/fingerprinting, never for security purposes; use SHA-256 or SHA-512 for security-relevant hashing
Alternatives
Full Evaluation Report
Detailed scoring breakdown, competitive positioning, security analysis, and improvement recommendations for CryptoJS.
Scores are editorial opinions as of 2026-03-06.