Prosecutors acknowledged that the sex was consensual, but accused him of misrepresenting himself.
The court agreed, sentencing Kashur despite acknowledging that his case was not "a classical rape by force".
"If she hadn’t thought the accused was a Jewish bachelor interested in a serious romantic relationship, she would not have co-operated," the judges said in their ruling.
"The court must protect the public interest against sophisticated criminals with a smooth tongue and sweet talking, who can lead astray innocent victims."
The Israeli criminal code mentions "deceit" as a possible aggravating factor in sexual assault cases and the verdict in Kashur's case is not the first time an Israeli court has sentenced a man for "rape by deception," according to several Israeli lawyers.
"The court must protect the public interest against sophisticated criminals with a smooth tongue and sweet talking, who can lead astray innocent victims"
The most notable case was in 2008, when Israel's high court of justice upheld the conviction of Zvi Sleiman, a man who impersonated a housing ministry official and promised women apartments and benefits in exchange for sex.
A rape conviction sentence could be upheld, the court ruled, when "a person lies does not tell the truth regarding critical matters to a reasonable woman".
Several other men have been convicted of "rape by deception" since that ruling.
But the Kashur case appears to be the first time a person's race has been used as the determining factor.
"In this case, the ruling seems to say that if a 'reasonable' Jewish woman knew a man was an Arab, then she would not make love to him," Abeer Baker, an attorney with Adalah, an organisation that advocates for Arab rights in Israel, said.
Baker called it a "dangerous precedent," saying it would allow the Israeli government to interfere in the private lives of citizens.
"It's interfering in a very intimate, personal decision," she said. "That should be made between two people. The court should not interfere."
Similar laws have been controversial in other countries, as well. A man in the United States was convicted in 2007 of impersonating his brother in order to have sex with his girlfriend. That conviction was overturned on appeal, though, after an appellate court ruled that rape laws apply only to non-consensual sex.
Kashur's case also highlights the open hostility with which many Israeli Jews view mixed relationships with Arabs, who make up one-fifth of the population of Israel.
A poll conducted in 2007 by Israel's Geocartography Institute found that more than 50 per cent of Israeli Jews thought marrying an Arab was "equal to national treason". Jews are legally forbidden to intermarry in Israel.
The Sunday Times reported in 2009 on a squad of "vigilantes" in the Jewish settlement of Pisgat Zeev. The group has patrolled the streets for more than a decade looking for mixed couples.
And in 2009, the town of Petah Tikva established a team of counsellors and psychologists to "rescue" Jewish women from relationships with Arab men.
The Israeli daily Maariv reported in February that Tel Aviv had launched a similar programme.
Gideon Levy, a liberal columnist with the Israeli newspaper Haaretz, said the "rape by deception" law would have been applied differently if a Jewish man had sex with an Arab woman under false pretences.
"Would he have been convicted of rape?" Levy asked. "The answer is: of course not."