広告が嫌いですか? 行く広告なし今日 

ChaCha20 Key Generator

開発者安全

広告・取り除く？

入力

出力

クライアント側

広告・取り除く？

ガイド

ChaCha20 Key Generator

Generate cryptographically secure ChaCha20 keys for use in stream cipher encryption. Produce 256-bit keys in hex or Base64 format, with optional initial counter values, in bulk batches of up to 10 keys at once. All generation uses the browser’s built-in crypto.getRandomValues() API for true randomness.

使い方

Select your preferred output format (hex or Base64), choose how many keys to generate (1–10), and optionally enable the initial counter field. Click 生成する to produce your keys instantly. Each key can be copied individually. Use the Reset button to clear all outputs.

特徴

256-bit keys – always 32 bytes, matching the ChaCha20 specification
Two output formats – hexadecimal (64 chars) or Base64 (44 chars)
Batch generation – generate 1 to 10 keys at once
Optional counter – include a random 32-bit initial counter value alongside the key
Cryptographically secure – 使用 crypto.getRandomValues(), not Math.random()
クライアントサイドのみ – keys are generated locally and never transmitted

広告・取り除く？

 よくある質問

What is ChaCha20 and how does it differ from AES?

ChaCha20 is a stream cipher designed by Daniel J. Bernstein as an alternative to AES. Unlike AES (a block cipher), ChaCha20 generates a keystream that is XOR’d with the plaintext, making it naturally suited to variable-length data without padding. ChaCha20 is faster than AES on hardware without AES-NI acceleration and is immune to timing attacks. It is used in TLS 1.3, WireGuard, and SSH as ChaCha20-Poly1305.
Why is ChaCha20 preferred over RC4 as a stream cipher?

RC4 has well-documented biases in its keystream, particularly in the first few bytes, which led to the BEAST and RC4NOMORE attacks against TLS. ChaCha20 uses a modern ARX (Add-Rotate-XOR) construction with 20 rounds that produces statistically uniform output with no known biases. The IETF standardised ChaCha20-Poly1305 in RFC 8439 specifically as a secure replacement for RC4 and older stream ciphers.
What is the role of the nonce and counter in ChaCha20?

ChaCha20 takes a 256-bit key, a 96-bit nonce, and a 32-bit initial counter. The nonce ensures that encrypting the same plaintext with the same key produces different ciphertext (critical for security). The counter allows seeking within the keystream without recomputing from the start, enabling efficient random access. The nonce must never be reused with the same key — nonce reuse completely breaks confidentiality.
How should ChaCha20 keys be stored and managed?

ChaCha20 keys must be treated as secrets with the same care as passwords. Store them in a secrets manager (HashiCorp Vault, AWS Secrets Manager, etc.), never in source code or version control. Rotate keys regularly and use envelope encryption for long-term storage: encrypt the ChaCha20 key itself with a master key derived from a KMS. Each key should be used with a unique nonce for every encryption operation.