Below is a list of bug bounty programs from various Bitcoin businesses and organizations. Please make sure to follow their terms and conditions before attempting to find security vulnerabilities! 

- [Bitcointalk.org](https://bitcointalk.org/index.php?topic=309785.msg3326091#msg3326091) - Varying amounts
- [Buttercoin](https://www.crowdcurity.com/buttercoin) - $50 - $1000
- [Circle Internet Financial](https://www.crowdcurity.com/circle) - $50 - $1000
- [Coinbase](https://coinbase.com/whitehat) - $1000 in BTC per bug! 
- [Coindrawer](https://www.coindrawer.com/whitehat/) - No minimum or maximum
- [Coinkite](https://coinkite.com/faq/responsible-disclosure) - Minimum of .25 BTC
- [Counterparty](https://www.crowdcurity.com/counterparty) - $20 - $1500
- [Crowdcurity](https://www.crowdcurity.com/users/crowdcurity/programs/crowdcurity-reward-program-ongoing) - $50 - $1000+ 
- [Justcoin](https://www.crowdcurity.com/users/justcoin/programs/justcoin-reward-program-ongoing) - $15 - $150
- [Opal Cryptocurrency](https://www.crowdcurity.com/opal-cryptocurrency) - 75 mBTC - 700 mBTC
- [PikaPay](https://www.pikapay.com/bitcoin-bounty/) - .001 to 100 BTC
- [Ripple](https://ripple.com/bug-bounty/) - Varying amounts
- [Vault of Satoshi](https://www.crowdcurity.com/users/vault-of-satoshi/programs/vault-of-satoshi-reward-program-ongoing) - $50 - $1000 in BTC
- [Zynga](http://company.zynga.com/security/whitehats) - For the props!