One2backup™ and the Blowfish Algorithm

security of your online backup will never be compromised

Of the hundreds of encryption algorithms available today, blowfish stands out as the industry leader and has been selected by One2backup™ as its encryption algorithm for its online data backup software needs.

Blowfish is a symmetric encryption algorithm designed in 1993 by Bruce Schneier as an alternative to existing encryption algorithms such as DES. Unlike DES, however, the Blowfish algorithm has a variable key length, which can be extended from 32 bits to 448 bits, making this a more secure alternative for data backups. Blowfish is a 64-bit cipher (i.e. a cryptographic key and algorithm are applied to a block of data rather than single bits) which fits in perfectly for our online data backup software needs.

Blowfish is a fast, free alternative to existing algorithms and has been analyzed considerably through years of peer review.

Length = Strength

It is easy to demonstrate that in the case of brute-force attack, the security increases together with the length of the key. If the key is 8 bits long, there are 2(to the power of 8), or 256 possible combinations. With a key of 40 bits this is increased to 2(to the power of 40), or one thousand billion combinations. The protection then resides on the time needed for a computer to perform its attack. Based on these premises as well as numerous industry trials, it is common opinion today that

  • 40-bit key algorithms are useless as they can be "cracked" within a few hours by an average personal computer.
  • 64-bit algorithms are safe today but will become threatened as technology evolves.
  • 128-bit and over algorithms are almost unbreakable. In other words, it would take millions of years to try every possible combination of bits in a 128-bit key.


The speed of the blowfish algorithm is also impressive. The table below illustrates the effective throughput of the algorithm and shows how even large key lengths result in much faster performance than other encryption algorithms.


backup software has a 128-bit key encryption
Speed Comparisons of Block Ciphers on a Pentium
Algorithm Clock cycles per round # of rounds # of clock cycles per byte encrypted Notes
Blowfish 9 16 18 Free, unpatented
Khufu/Khafre 5 32 20 Patented by Xerox
RC5 12 16 23 Patented by RSA Data Security
DES 18 16 45 56-bit key
IDEA 50 8 50 patented by Ascom-Systec
Triple-DES 18 48 108 very popular


One2backup™ considered many factors when choosing Blowfish as its encryption technology for its online data backup needs, including peer review, speed and key strength. It is clear that Blowfish will set the standard for years to come, and will continue to be the preferred encryption algorithm for corporations worldwide.