• Legacy ciphers - DES/3DES-as-DES, Blowfish, CAST5/CAST6, RC2, RC4, SEED, and CFB-1 mode • MD5-based key derivation e.g. Cipher#pkcs5_keyivgen (which defaults to MD5) • Undersized keys - RSA below 2048 bits for signing, HMAC keys shorter than 112 bits